# Purplelink LLC

> Purplelink LLC is a one-person software studio in Atlanta, Georgia, founded in 2026 by Benjamin Ampel, that makes native Mac apps and free web tools. Mac apps (all with a free 7-day trial in the same download, then a one-time license key): ModernTex ($19.99, a LaTeX editor), Outbound Veil ($29.99, a menu-bar check for personal information in what you type), Legroom ($9.99, a menu-bar disk space readout and cleaner), Keyfeel ($9.99, recorded keyboard-switch sounds as you type), and the Mac Suite ($54.99, all four plus a lifetime Vitae Plus). Also Vitae (a free Mac app for tracking submissions, grants and your CV, with an optional Plus subscription), Paper Review (AI pre-submission manuscript review, $9-$15), Scholar Utility Belt (a Chrome extension for Google Scholar, free core with an optional Pro tier), free in-browser LaTeX and BibTeX tools, GlobePin (a free iOS travel-mapping app) and Haea (an on-device iOS health app in development).

## Company

- **Legal name:** Purplelink LLC
- **Type:** Georgia LLC (NAICS 541511 — Custom Computer Programming Services)
- **Location:** 8735 Dunwoody Place #12398, Atlanta, GA 30350
- **Founded:** 2026
- **Contact:** ben@purplelink.llc
- **LinkedIn:** https://www.linkedin.com/company/purplelink-llc/
- **GitHub:** https://github.com/purplelink-llc
- **Bluesky:** https://bsky.app/profile/purplelink.llc (custom-domain-verified handle `@purplelink.llc`)
- **CEO:** Benjamin Ampel
- **Website:** https://purplelink.llc/
- **Mission:** Making software that lasts.

## What Purplelink builds

1. **Mac apps** — ModernTex (LaTeX manuscript editor), Outbound Veil (a menu-bar checker for personal information in what you type), Legroom (a menu-bar disk space readout and cleaner), Keyfeel (recorded keyboard-switch sounds, mouse clicks, scroll ticks and optional trackpad haptics, in the menu bar), the Mac Suite bundle, and Vitae (free academic record keeping).
2. **Paid AI manuscript tools** — Paper Review and six smaller pre-submission checks, $2-$15 per use, no account.
3. **Free in-browser tools and guides** — LaTeX compilation, BibTeX validation, citation generation, format conversion, and how-to guides for academic writing.
4. **iOS apps** — GlobePin (travel mapping, shipping) and Haea (on-device health analytics, in development).

## Products — available now

### ModernTex (macOS)
- **Platform:** macOS 14+
- **Category:** Productivity / academic writing
- **Description:** A native macOS LaTeX manuscript studio for academic researchers. Combines multi-file manuscript editing, tightly synchronized PDF preview, intelligent compile modes (Fast/Live/Full), citation management and BibTeX autocomplete, revision snapshots, plain-language error diagnostics, and submission-readiness checks in one coherent interface.
- **Target users:** PhD students, faculty, and technical coauthors writing serious LaTeX manuscripts
- **Pricing:** Free 7-day trial (the complete app, no account), then $19.99 USD one-time to keep. No subscription. All updates are included, forever.
- **Privacy:** No cloud sync, no data collection
- **Status:** Shipping. Current version 1.4.0, which makes ModernTex one download, free for seven days and then a license key, with copies already bought left as they are; 1.3.6 made the free trial show the right price and adds one note near the end of the trial; 1.3.5 made the plain Light and Dark themes change the whole window and toolbar tooltips drawn by the app; 1.3.4 made Command-click in the PDF scroll the editor again and the toolbar fit narrow windows; 1.3.3 fixed jumping between the editor and the PDF and added a PDF-only layout, a sidebar toggle and plain light and dark editor themes; 1.3.2 changed the key used to verify updates; 1.3.1 added a unified Settings window (editor font, line spacing, syntax colors, Zen mode); 1.3.0 added a visual Table Editor; 1.2.0 added the TikZ Designer. Version 1.0.0 released 2026-09-04; the free trial arrived in 1.0.2.
- **Trial and purchase:** https://purplelink.llc/moderntex/
- **Setup guide:** https://purplelink.llc/moderntex/start/ (first ten minutes: install, MacTeX or TinyTeX setup, first build, first error, venue templates, submission checks)
- **Requirements:** macOS 14 (Sonoma) or later, Apple silicon or Intel, and a TeX distribution such as MacTeX or TinyTeX (ModernTex offers a one-click TinyTeX install if none is found). Signed, notarized disk image.
- **Updates:** The app checks once a day and installs in place; updates are included in the purchase.
- **Key differentiators:** Plain-language LaTeX error explanations; submission-readiness checks for journal/conference requirements; native macOS (not Electron, not web); academic manuscript workflow as first-class feature

### Outbound Veil (macOS)
- **Platform:** macOS 14 (Sonoma) or later, Apple silicon and Intel
- **Category:** Privacy utility
- **Description:** A Mac menu-bar app that checks what you type for personal information before you send it: names, street addresses, phone numbers, email addresses, Social Security numbers, card numbers, passport and driver's license numbers, tax and bank identifiers, dates of birth, medical record numbers and IBANs. It shows a badge when it finds something, and you redact, ignore, or in apps you choose have it hold the send key until you decide.
- **Pricing:** Free 7-day trial (the complete app, no account), then $29.99 once to keep, updates included. One download for everyone: after the trial the app asks for a license key, sent in the receipt email.
- **Privacy:** The checking runs on the Mac. Nothing typed is stored or sent, there are no accounts and no analytics. Apart from the download, the only network use is the update check.
- **Limits:** Latin-script names only; it also flags public figures' names; it will miss some things; it cannot read the body of a new message in Apple Mail. It lowers the chance of a mistake and is not a compliance product.
- **Credit:** The detection model is Rampart by National Design Studio (CC BY 4.0), https://github.com/nationaldesignstudio/rampart. Purplelink ported its processing code to Swift and added rules for dates of birth, medical record numbers and IBANs; the model file is unchanged.
- **Trial and purchase:** https://purplelink.llc/outbound-veil/
- **Setup guide:** https://purplelink.llc/outbound-veil/start/ (first ten minutes: install, Accessibility, a first check on a made-up note, redacting, choosing apps, trial and updates)
- **Tested apps:** https://purplelink.llc/outbound-veil/works-in/ (each app and field it has been tried in, with a status of tested and works, tested and does not work, or not tested. Works in TextEdit, Notes, Messages, Microsoft Word and Chrome text areas including the ChatGPT and claude.ai prompt boxes; cannot read the body of a new message in Apple Mail; off by default in Terminal; Safari, Slack and VS Code not tested)
- **Permissions explained:** https://purplelink.llc/guides/mac-privacy-permissions-explained/ (what Accessibility and Input Monitoring allow, how to review them; Outbound Veil asks for Accessibility, and for Input Monitoring only if send hold is on)

### Legroom (macOS)
- **Platform:** macOS 14 (Sonoma) or later, Apple silicon and Intel
- **Category:** Disk space utility
- **Description:** A Mac menu-bar app that shows free disk space, warns before the disk fills, and cleans the folders and developer caches you choose. Cleaning runs through rules; each rule shows a preview of what it would remove and needs your approval, and either moves items to the Trash or deletes them. It recommends known caches, scans code projects for old build folders, shows what grew over 1, 7 and 30 days from daily measurements, suggests rules weekly or monthly, and includes a Space Map (a sunburst chart of where space goes, with Move to Trash), Find Files (large, old and duplicate files; duplicates always keep one copy; Trash only) and an Uninstaller (lists the files an app keeps in the Library folder with sizes, plus support files left by apps that are gone; items start ticked only when named exactly for the app; Trash only, after a confirmation sheet that measures again).
- **Pricing:** Free 7-day trial, then $9.99 once to keep. After the trial the menu-bar readout and low-space alerts stay free, and a license key (sent in the receipt email) unlocks the rest, including the Uninstaller, in the same download.
- **Privacy:** No account, no analytics. Measurements, rules and the trial clock stay on the Mac. The only network use is the daily update check that every copy makes and the Buy link.
- **Limits:** It does not speed up a Mac, does not run commands (leftovers in the system Library are shown with a command to copy and are not removed), does not clean inside system folders apart from the Uninstaller's items in the user Library, and does not scan as an administrator. The Uninstaller never offers Apple apps, system apps or Legroom itself. Full Disk Access is optional; without it the Uninstaller skips the Containers, Group Containers and Cookies folders.
- **Trial and purchase:** https://purplelink.llc/legroom/
- **Guide:** https://purplelink.llc/guides/show-free-disk-space-mac-menu-bar/ (how to see free space with Finder, Storage settings, Disk Utility and df, and the menu-bar apps compared)
- **Permissions explained:** https://purplelink.llc/guides/mac-privacy-permissions-explained/ (what Full Disk Access allows, what Apple said about it on 2026-10-02, how to review it; Legroom never requires it)

### Keyfeel (macOS)
- **Platform:** macOS 13 or later, Apple silicon and Intel
- **Category:** Typing and sound utility, menu bar
- **Description:** A Mac menu-bar app that plays recorded keyboard-switch sounds when you press a key, with mouse-click sounds, speed-aware scroll ticks and optional trackpad haptics (only while a finger is on the trackpad). Recorded profiles Tactile, Cherry MX Brown and Dome, a different recording each press, per-key pitch and left-to-right stereo, sounds for the space bar and Return, a click ripple, per-app silence, silence while the microphone is in use, and import of your own sound.
- **Pricing:** Free 7-day trial (the complete app, no account), then $9.99 once to keep, updates included. One download for everyone: after the trial the app asks for a license key, sent in the receipt email. 14-day refund.
- **Privacy:** It reads key codes, never the characters you type. It works offline. It needs the macOS Input Monitoring permission. No account, no analytics.
- **Status:** Shipping, version 1.3.1 (October 2026).
- **Trial and purchase:** https://purplelink.llc/keyfeel/
- **Comparison:** https://purplelink.llc/guides/best-keyboard-sound-apps-for-mac/ (Klack, KeyOpera, Thock, Mechvibes and others, by price, sounds, permissions and limits)
- **Mechvibes sound packs:** https://purplelink.llc/guides/mechvibes-sound-packs-on-mac/ (Keyfeel imports Mechvibes packs in the original format, not the MechvibesDX V2 format; how to import, what does not carry over)
- **Permissions explained:** https://purplelink.llc/guides/mac-privacy-permissions-explained/ (Keyfeel needs Input Monitoring and reads key codes, never characters; Accessibility is optional for two features)

### Mac Suite (macOS bundle)
- **Contents:** ModernTex, Outbound Veil, Legroom, Keyfeel and a lifetime Vitae Plus key.
- **Pricing:** $54.99 once. 14-day refund. Each app is the same single download with a 7-day trial; the license keys arrive in the receipt email.
- **Page:** https://purplelink.llc/suite/

### Vitae (macOS)
- **Platform:** macOS 15 (Sequoia) or later
- **Category:** Academic research management
- **Description:** A local-first Mac app for academics: track journal and conference submissions, grants, projects and collaborators, and generate your CV from that record.
- **Pricing:** Free. Optional Vitae Plus subscription, $2.99/month or $23.99/year with a 7-day free trial, adds reports, Word templates, a revision workspace and Shareables. Core record-keeping stays free.
- **Status:** Shipping, version 1.0.3. Apple-notarized download, no App Store required.
- **Product page:** https://purplelink.llc/vitae/
- **Vitae Plus:** https://purplelink.llc/vitae/plus/

### GlobePin (iOS)
- **Platform:** iOS 17+
- **Bundle ID:** com.globepin.app
- **Category:** Travel
- **Description:** A travel mapping app for tracking every place visited, every flight taken, and every destination on the list. Features interactive map visualization with 3D globe view, flight statistics dashboards, travel goal tracking, anniversary reminders for visits, and shareable travel postcards.
- **Target users:** Frequent travelers who want a complete personal travel record
- **Pricing:** Free. No subscription and no in-app purchase.
- **Sync:** iCloud sync via CloudKit (no Purplelink account required)
- **Status:** Shipping. Version 1.0 released on the App Store 2026-09-03.
- **Download:** https://apps.apple.com/us/app/globepin/id6762313540
- **Product page:** https://purplelink.llc/globepin/
- **Requirements:** iPhone or iPad running iOS 17.0 or later
- **Key differentiators:** 3D globe view for route visualization; complete flight log with stats; travel goals tied to actual history; anniversary reminders; iCloud sync without a separate account; no social network features

## Products in development

### Haea (iOS)
- **Platform:** iOS 17+
- **Bundle ID:** com.BAmpel.Haea
- **Category:** Health & fitness
- **Description:** A comprehensive on-device health analytics platform. Integrates sleep, nutrition, weight, exercise, and biometric data to surface patterns and trends through advanced ML models including Kalman filtering, TDEE calculation, circadian rhythm intelligence, Granger causality analysis, and VO₂ max tracking.
- **Target users:** Health-conscious individuals who want advanced analytics without giving up their data
- **Pricing:** Free tier + Premium ($1.99/month or $14.99/year)
- **Privacy:** No cloud sync, no third-party SDKs, no analytics, on-device only, HIPAA-ready architecture
- **Status:** In active development, expected 2026
- **Waitlist:** https://purplelink.llc/haea/
- **Key differentiators:** Full on-device ML (Kalman filtering, Granger causality, biological age estimation); no cloud transmission of health data; privacy-first architecture as a core design constraint, not an add-on

### Binnacle (macOS)
- **Platform:** macOS 14+
- **Description:** A local-first Mac app for solo founders, indie developers and creators. Keeps a double-entry ledger, imports income and expenses using your own API keys (Stripe, Mercury, Plaid, Square, Gumroad, Lemon Squeezy, Paddle, YouTube, App Store Connect, CSV), and estimates federal quarterly taxes for 2025 and 2026. It does not file returns and is not tax advice.
- **Pricing:** Planned at about $49 per year with a 14-day trial; not final.
- **Status:** Private beta. Waitlist only, not yet available to download.
- **Waitlist:** https://purplelink.llc/binnacle/
- **Terms:** https://purplelink.llc/binnacle/terms/ (version 2026-09-29-1)

## Open source

### Scholar Utility Belt
- **Type:** Browser extension (Google Chrome)
- **Purpose:** Adds journal quality badges (ABDC, FT50, UTD24, SJR), citation velocity, author metrics (h-index, g-index), academic lineage trees and retraction alerts to Google Scholar. Rankings are bundled locally; no analytics, no account. Pro licensing goes through ExtensionPay.
- **Pricing:** Free core (ISC license). Optional Pro: $40 once, $3 per month or $20 per year. Installs made before v0.6.0 keep all earlier features free.
- **Adoption:** About 1,000 users, rated 4.5/5 from 16 ratings on the Chrome Web Store
- **Chrome Web Store:** https://chromewebstore.google.com/detail/scholar-utility-belt/omcogfcgldfmihfogbffflbocdbjockn

## Pages

- Home: https://purplelink.llc/
- All products with prices: https://purplelink.llc/products/
- Scholar Utility Belt (Chrome extension, free core): https://purplelink.llc/scholar-utility-belt/
- Research desk (recommended books for academic writers): https://purplelink.llc/desk/
- Guide, using AI to check your own manuscript (publisher and venue policies compared): https://purplelink.llc/guides/ai-policy-checking-your-own-manuscript/
- ModernTex (macOS, free 7-day trial then $19.99, shipping): https://purplelink.llc/moderntex/
- Outbound Veil (macOS, free 7-day trial then $29.99): https://purplelink.llc/outbound-veil/
- Legroom (macOS, free 7-day trial then $9.99): https://purplelink.llc/legroom/
- Keyfeel (macOS, free 7-day trial then $9.99, recorded keyboard-switch sounds as you type): https://purplelink.llc/keyfeel/
- Mac Suite (macOS, $54.99 once: ModernTex, Outbound Veil, Legroom, Keyfeel and Vitae Plus for life, 14-day refund): https://purplelink.llc/suite/
- Vitae (macOS, free app; optional Vitae Plus subscription from $2.99 a month, shipping): https://purplelink.llc/vitae/
- Paper Review (AI manuscript review, from $9): https://purplelink.llc/tools/paper-review/
- Paper Review example report, section by section: https://purplelink.llc/tools/paper-review/sample/
- Free tools: https://purplelink.llc/tools/
- Daily games and unlimited rated puzzles (Linkle, Quadlink, Daily Five, Daily Photo, Daily Chess, Sudoku, crossword, Daily Stars, Chess Puzzles, Sudoku Unlimited, leaderboards, Landlink, Atomlink, Prizelink, Citylink, Peaklink, Codelink, Thinkerlink, Riverlink, Wildlink, Lockerlink, Gridlink, Under the Cap; free, no account needed): https://purplelink.llc/games/
  - Linkle: Linkle is a free daily word game. https://purplelink.llc/games/linkle/
  - Quadlink: Quadlink is a free daily word game where you solve four hidden five-letter words at once in nine guesses. https://purplelink.llc/games/quadlink/
  - Daily Five: Daily Five is a free daily trivia quiz with five multiple-choice questions. https://purplelink.llc/games/daily-five/
  - Daily Photo: Daily Photo is a free daily geography game. https://purplelink.llc/games/daily-photo/
  - Daily Chess: Daily Chess is a free daily chess tactics puzzle drawn from the Lichess puzzle database. https://purplelink.llc/games/daily-chess/
  - Sudoku: Daily Sudoku is a free daily Sudoku with exactly one solution. https://purplelink.llc/games/sudoku/
  - Daily Crossword: Daily Crossword is a free daily themeless crossword puzzle. https://purplelink.llc/games/crossword/
  - Daily Stars: Daily Stars is a free daily horoscope with a short reading for each of the twelve zodiac signs. https://purplelink.llc/games/daily-stars/
  - Chess Puzzles: Chess Puzzles is a free, unlimited chess tactics trainer. https://purplelink.llc/games/chess-puzzles/
  - Sudoku Unlimited: Sudoku Unlimited is a free Sudoku with no daily limit. https://purplelink.llc/games/sudoku-unlimited/
  - Leaderboards: The Purplelink puzzle leaderboards list the highest ratings in Chess Puzzles and Sudoku Unlimited, plus the biggest rating gains this week. https://purplelink.llc/games/leaderboard/
  - Landlink: Landlink is a free daily geography game. https://purplelink.llc/games/landlink/
  - Atomlink: Atomlink is a free daily chemistry game. https://purplelink.llc/games/atomlink/
  - Prizelink: Prizelink is a free daily game about Nobel laureates. https://purplelink.llc/games/prizelink/
  - Citylink: Citylink is a free daily geography game. https://purplelink.llc/games/citylink/
  - Peaklink: Peaklink is a free daily geography game about mountains. https://purplelink.llc/games/peaklink/
  - Codelink: Codelink is a free daily game about programming languages. https://purplelink.llc/games/codelink/
  - Thinkerlink: Thinkerlink is a free daily game about famous scientists. https://purplelink.llc/games/thinkerlink/
  - Riverlink: Riverlink is a free daily geography game about rivers. https://purplelink.llc/games/riverlink/
  - Wildlink: Wildlink is a free daily game about animals. https://purplelink.llc/games/wildlink/
  - Lockerlink: Lockerlink is a free daily sports puzzle: link two players from any era through a chain of real teammates (NBA, NFL, MLB, NHL). https://purplelink.llc/games/lockerlink/
  - Gridlink: Gridlink is a free daily sports grid: name a player who fits each row and column clue, in nine guesses. https://purplelink.llc/games/gridlink/
  - Under the Cap: Under the Cap is a free sports team builder: pick a roster from any era under a budget and play a full season. https://purplelink.llc/games/under-the-cap/
  - Tanklink: Tanklink is a free daily artillery game: set angle and power, read the wind and destroy the enemy tanks in eight shots. https://purplelink.llc/games/tanklink/
  - Sports games hub: free daily NBA, NFL, MLB and NHL puzzles (Lockerlink, Gridlink, Under the Cap). https://purplelink.llc/games/sports/
  - Teammate chains between stars of different eras: https://purplelink.llc/games/sports/nba-teammate-chains/ , https://purplelink.llc/games/sports/nfl-teammate-chains/ , https://purplelink.llc/games/sports/mlb-teammate-chains/ , https://purplelink.llc/games/sports/nhl-teammate-chains/
- Guides: https://purplelink.llc/guides/
- GlobePin (iOS, free with ads, Pro $14.99 once, shipping): https://purplelink.llc/globepin/
- Haea (iOS, in development): https://purplelink.llc/haea/
- Kits (downloadable automation systems): https://purplelink.llc/kits/
- Daily Digest (curated reading on cybersecurity, AI, research and entrepreneurship): https://purplelink.llc/blog/digest/
- About: https://purplelink.llc/about/
- Support (how to reach Ben, refunds, lost keys and purchases, update notes, data handling): https://purplelink.llc/support/
- Blog: https://purplelink.llc/blog/
- Press: https://purplelink.llc/press/
- Privacy Policy: https://purplelink.llc/privacy/
- Changelog: https://purplelink.llc/changelog/
- Find a purchase (lost ModernTex key or kit download): https://purplelink.llc/recover/
- Pricing (every price on one page): https://purplelink.llc/pricing/
- Paper Review by field (what each domain profile checks): https://purplelink.llc/tools/paper-review/machine-learning/ , https://purplelink.llc/tools/paper-review/biomedicine/ , https://purplelink.llc/tools/paper-review/psychology/ , https://purplelink.llc/tools/paper-review/chemistry/
- For labs and departments (volume packs, invoices, purchase orders, data handling): https://purplelink.llc/labs/
- Security and data handling (what each product does with a file, subprocessor table, encryption, deletion timing, breach notice; DPA and HECVAT Lite on request): https://purplelink.llc/security/

## Frequently asked questions

**When do Purplelink's apps ship?**
ModernTex (macOS) came out on 2026-09-04, has a free 7-day trial, and sells for $19.99 at https://purplelink.llc/moderntex/. Vitae (macOS) is free at https://purplelink.llc/vitae/, with an optional Vitae Plus subscription at $2.99 a month or $23.99 a year. GlobePin (iOS) came out on 2026-09-03 and is free with ads at https://apps.apple.com/us/app/globepin/id6762313540, and a one-time $14.99 Pro purchase removes the ads. Haea is still in development, with a waitlist on its product page.

**What platforms do the apps support?**
ModernTex is a macOS app (macOS 14+). Vitae is a macOS app (macOS 15+). GlobePin and Haea are iOS apps (iOS 17+).

**Does Haea send my health data to a server?**
No. All of Haea's data stays on-device. There is no cloud sync to Purplelink's infrastructure, no third-party SDKs, and no analytics. Your health data never leaves your iPhone.

**Does Haea work with Apple Health?**
Yes. Haea reads data from Apple Health including sleep, nutrition, weight, exercise, heart rate, HRV, and blood oxygen.

**Is Haea HIPAA-compliant?**
Haea is a consumer app, not a covered entity under HIPAA. However, its architecture exceeds typical health app privacy standards: all data is on-device with no cloud transmission.

**Does GlobePin require an account?**
No. GlobePin syncs via iCloud (CloudKit) using your existing Apple ID. No separate Purplelink account is required.

**Is ModernTex a subscription?**
No. ModernTex is $19.99 once, with all updates included, forever. There is no subscription and no account to create. Buy it at https://purplelink.llc/moderntex/.

**How much does ModernTex cost?**
$19.99 USD, a one-time purchase through Stripe. The download link arrives as soon as payment clears.

**What does ModernTex need to run?**
macOS 14 (Sonoma) or later on Apple silicon or Intel, plus a TeX distribution such as MacTeX or TinyTeX. ModernTex finds the distribution on first launch and tells you if neither is installed.

**How is ModernTex different from TeXShop or Overleaf?**
It is a native macOS app built around the academic manuscript rather than the file. TeXShop dates from 2000 and Overleaf is a collaborative web app; ModernTex adds multi-file manuscript navigation, a PDF preview that stays in sync, BibTeX completion that searches by author or title, plain-language compile diagnostics, and submission-readiness checks.

**Who built Purplelink?**
Purplelink LLC was founded by Benjamin Ampel in Atlanta, Georgia in 2026. It is a one-person studio.

**Will Purplelink sign a data processing addendum or complete a HECVAT?**
Yes. A DPA, the subprocessor list and a completed HECVAT Lite or a department's own vendor questionnaire are available on request from ben@purplelink.llc. The plain-language summary of data handling per product is at https://purplelink.llc/security/.

**How do I contact Purplelink?**
Email ben@purplelink.llc for product inquiries, press, or general questions.

## Notes

- Project inquiries: ben@purplelink.llc with subject "Purplelink LLC"
- The company is a sole-proprietor LLC operated out of Atlanta, Georgia
- **Website analytics:** the purplelink.llc marketing site uses Cloudflare Web Analytics (cookieless, no PII, aggregate page-view counts only). All of Purplelink's apps remain analytics-free as described per product above.

## Paid tools

### Paper Review (multiple tiers)
- **URL:** https://purplelink.llc/tools/paper-review/
- **Standard:** $9 — single-pass 4-persona red team + figure scan + live citation check + annotated PDF download. **Anonymity Check bundled free.**
- **Standard + Journal Pack:** $11 — adds a compliance check against the target journal's submission rules (25 venues: NeurIPS, ICML, ICLR, AAAI, TMLR, JMLR, Nature, Science, Cell, PLOS ONE, Nature Medicine, JAMA, NEJM, The Lancet, The BMJ, Psychological Science, JPSP, Cognition, Academy of Management Journal, JACS, Angewandte Chemie, Nature Materials, Nature Chemistry, ACS Nano, Advanced Materials). Anonymity Check still bundled.
- **Deep Review:** $15 — two-pass adversarial debate where each persona sees the others' first-pass findings, plus bundled Anonymity Check and Journal Pack.
- **Volume packs:** 5 Standard review tokens for $38 or 20 for $150 at https://purplelink.llc/tools/paper-review/packs/. Tokens emailed at purchase, never expire.
- **Delivery:** Async polling page; typically 4-8 minutes per manuscript (standard) or 10-15 minutes (deep). The report is emailed as a PDF when the review finishes, through Resend, to the address on the Stripe receipt. The manuscript is never emailed.
- **Free reference check:** Before paying, upload the PDF on the Paper Review page to see how many references CrossRef confirms and up to three quoted findings (unmatched references, DOIs that point to another title, anonymity leftovers). No AI, no account; the file is not sent to Anthropic and is discarded after the check.
- **Output:** Markdown report with What's Working / Critical Blind Spots (with per-finding confidence tags) / Data-to-Claim Contradictions / Rectification Checklist (A/B/C priority) / True Novelty Estimate / Reference Verification Summary / Panel Transcript. Plus an annotated PDF with sticky-note comments at the right pages.
- **Privacy disclosure:** Manuscript sent to Anthropic Claude API (30-day input retention for abuse monitoring; never used for training). The report is emailed to the buyer as a PDF; Purplelink deletes the manuscript and the online copy 30 minutes after the result is first opened, or after 24 hours if it never is.
- **Refunds:** Full refund within 14 days; email ben@purplelink.llc.

### Cover Letter Generator — $2
- **URL:** https://purplelink.llc/tools/cover-letter/
- Draft journal cover letter from abstract + target journal name. Privacy-preserving: never receives full manuscript.

### Anonymity Check — $2
- **URL:** https://purplelink.llc/tools/anonymity-check/
- Scans manuscript for identifying info before double-blind submission (author names, institutions, funder acknowledgements, self-citation patterns, IRB numbers, author-owned URLs).

### Citation Gap Analysis — $3
- **URL:** https://purplelink.llc/tools/citation-gap/
- Reverse citation check: finds prior art the manuscript should cite but doesn't.

### Revision Review — $2
- **URL:** https://purplelink.llc/tools/paper-review/revision/
- Second-pass review after revisions. Requires the original review's Markdown file. Tracks which checklist items were addressed and flags new issues introduced by the revision.

### Response to Reviewers — $6
- **URL:** https://purplelink.llc/tools/response-review/
- Three-persona AI panel that red-teams the author's response letter: per-comment verdicts, tone concerns, missing replies, accept/revise prediction.

### Resume Review — $5
- **URL:** https://purplelink.llc/tools/resume-review/
- Three-persona AI critique of a resume: ATS Screener, Hiring Manager Skeptic, Recruiter Red Flags. Results in minutes.

### Receipts and invoices
- Available on the Paper Review status page after delivery via "Get invoice for reimbursement" button. PDF invoice generated through Stripe, emailed via Resend. Custom tax-ID line supported for institutional reimbursement.

## Tools (free web tools)
- LaTeX to PDF: https://purplelink.llc/tools/latex-to-pdf/ — compile a .tex file to PDF (pdfLaTeX/XeLaTeX), files never stored.
- LaTeX Diff: https://purplelink.llc/tools/latex-diff/ — compare two .tex versions, output a marked-up PDF via latexdiff, files never stored.
- LaTeX to Word: https://purplelink.llc/tools/latex-to-word/ — convert a .tex paper to a standard double-spaced Word .docx manuscript, optional anonymize, files never stored.
- Word to LaTeX: https://purplelink.llc/tools/word-to-latex/ — convert a Word .docx into LaTeX source, files never stored.
- Markdown to PDF: https://purplelink.llc/tools/markdown-to-pdf/ — render Markdown to a typeset PDF, files never stored.
- BibTeX Builder: https://purplelink.llc/tools/bib-builder/ — generate BibTeX entries from a DOI or arXiv ID, nothing stored.
- BibTeX Validator: https://purplelink.llc/tools/bib-validator/ — check a .bib file for syntax errors and missing required fields, processed on Purplelink's server and not stored.
- Citation Generator: https://purplelink.llc/tools/citation-generator/ — build IEEE, APA, MLA, and Chicago citations from entry fields, runs in your browser.
- Reference Converter: https://purplelink.llc/tools/reference-converter/ — convert references between BibTeX, RIS, and other formats, runs in your browser.
- Equation Renderer: https://purplelink.llc/tools/equation-renderer/ — render LaTeX math to an image; the equation is compiled on Purplelink's server and not stored.
- LaTeX Table Generator: https://purplelink.llc/tools/latex-table-generator/ — build LaTeX tabular code from a visual grid, runs in your browser.
- Word & Character Counter: https://purplelink.llc/tools/word-counter/ — count words, characters, sentences, and reading time, the text is processed on Purplelink's server and not stored.
- Thesis Format Checker: https://purplelink.llc/tools/thesis-format-checker/ — checks a thesis or dissertation PDF for page size, margins against the minimums you enter, body font size, embedded fonts, page numbers and their sequence, line spacing and front-matter headings; the PDF is read in the browser and never uploaded.
- Replication Package Checker: https://purplelink.llc/tools/reproducibility-checker/ — checks a replication package .zip for a top-level README and the Social Science Data Editors' template sections, a license, pinned dependencies, a main script, absolute paths, random seeds, data files named in code but missing, output folders and stray files; the zip is read in the browser, never uploaded, and no code is run.
- Camera-Ready PDF Checker: https://purplelink.llc/tools/camera-ready-checker/ — checks the final PDF of an accepted paper for fonts that are not embedded or are Type 3 (with pages), page size, page count against the limit you enter, margins, page numbers and running heads, PDF title and author metadata, blind-submission leftovers, links and file size, with presets for IEEE conferences, ACM sigconf, Springer LNCS and NeurIPS sourced from the publishers' author pages; the PDF is read in the browser and never uploaded, and it does not replace IEEE PDF eXpress or ACM TAPS.
- Abstract Checker: https://purplelink.llc/tools/abstract-checker/ — an abstract's word count against the limit of 25 journals and conferences (NeurIPS, ICML, Nature, JAMA, NEJM, JACS and others), with the sections and reference style each expects; runs in your browser.
- PDF Tools: https://purplelink.llc/tools/pdf-tools/ — merge, split, and compress PDF files, files never stored.
- Metadata Cleaner: https://purplelink.llc/tools/metadata-cleaner/ - removes author names, GPS positions, camera details, comment and tracked-change authors, thumbnails and edit history from JPG, PNG, WebP, GIF, TIFF, SVG, PDF, DOCX, XLSX, PPTX, OpenDocument and MP4/MOV files, covers faces or text in a picture, and strips hidden characters from pasted text; everything runs in the browser in a background worker, files are never uploaded, and each result is re-read and checked to still open.
- File to Markdown: https://purplelink.llc/tools/file-to-markdown/ - convert PDF, Word, PowerPoint, Excel, HTML, CSV, or EPUB to Markdown, files never stored.
- PDF to Structured Data: https://purplelink.llc/tools/pdf-structure/ - convert a PDF to reading-order Markdown and RAG-ready JSON (tables, math as LaTeX, figure captions), powered by OpenDataLoader (Apache-2.0), files never stored.
- Response to reviewers template: https://purplelink.llc/tools/response-letter-template/ - paste the reviewer comments and get a response letter with every comment numbered and quoted (Markdown, LaTeX or plain text); runs in the browser.
- Submission Checklist: https://purplelink.llc/tools/submission-checklist/ - twelve pre-submission checks for a manuscript, each linked to the tool that does it; progress saved in the browser.
- LaTeX templates by venue: https://purplelink.llc/templates/ - IEEEtran (conference), ACM acmart, NeurIPS, Elsevier elsarticle and APA 7 (apa7): compilable skeletons with a downloadable starter (main.tex and references.bib), key class options and submission pitfalls.
- LaTeX error messages: https://purplelink.llc/latex-errors/ - twelve common LaTeX errors and warnings, each with a real pdfLaTeX log excerpt, the causes in order of likelihood with before and after examples, and how to find the line.
- LaTeX error, Undefined control sequence: https://purplelink.llc/latex-errors/undefined-control-sequence/ - TeX met a command name it has no definition for. Usually the name is misspelled or the package that defines it is not loaded.
- LaTeX error, Missing $ inserted: https://purplelink.llc/latex-errors/missing-dollar-inserted/ - TeX found something that only works in math mode while it was setting ordinary text, so it switched to math mode on its own.
- LaTeX error, File `x.sty' not found: https://purplelink.llc/latex-errors/file-not-found/ - LaTeX asked for a package, class or input file and could not find it in the project folder or in the TeX distribution.
- LaTeX error, Missing \begin{document}: https://purplelink.llc/latex-errors/missing-begin-document/ - LaTeX found something to print before \begin{document}. The line is usually there; something printable sits above it.
- LaTeX error, Runaway argument: https://purplelink.llc/latex-errors/runaway-argument/ - TeX was reading the argument of a command and ran out of file or paragraph before it found the closing brace.
- LaTeX error, Extra alignment tab has been changed to \cr: https://purplelink.llc/latex-errors/extra-alignment-tab/ - A table or matrix row has more & separators than the column specification allows.
- LaTeX error, Misplaced alignment tab character &: https://purplelink.llc/latex-errors/misplaced-alignment-tab/ - TeX found an & outside a table or alignment. For an ampersand in text, type \&.
- LaTeX error, LaTeX Error: Environment x undefined: https://purplelink.llc/latex-errors/environment-undefined/ - A \begin{...} names an environment LaTeX has no definition for.
- LaTeX error, Citation `x' undefined: https://purplelink.llc/latex-errors/citation-undefined/ - LaTeX found a \cite key with no bibliography entry to match on this run, so the PDF shows a question mark where the citation should be.
- LaTeX error, Overfull \hbox: https://purplelink.llc/latex-errors/overfull-hbox/ - TeX could not break a paragraph without letting one line stick out past the right margin. The number in the message says by how much.
- LaTeX error, Paragraph ended before \x was complete: https://purplelink.llc/latex-errors/paragraph-ended-before-complete/ - TeX was reading a command's argument and reached a blank line before the closing brace.
- LaTeX error, Too many }'s / Missing } inserted: https://purplelink.llc/latex-errors/too-many-closing-braces/ - Two messages for one problem: braces that do not pair up. One reports a closing brace too many, the other a group that was never closed.
- Reference formats by venue: https://purplelink.llc/format/ - reference style, BibTeX style file and template for 26 journals and conferences, grouped by field, each checked against the venue's own author instructions.
- JMIS reference format: https://purplelink.llc/format/references-for-jmis/ - a numbered list in alphabetical order, cited as [9]. The journal's own rules, three real examples, and a .bib checker. Checked 2026-10-01.
- JAIS reference format: https://purplelink.llc/format/references-for-jais/ - APA 7th edition, author-date. The journal's own rules, three real JAIS examples in APA 7, and a .bib checker. Checked 2026-10-01.
- EJIS reference format: https://purplelink.llc/format/references-for-ejis/ - format-free submission, any consistent citation style, and a .bib file required with LaTeX. Rules, examples, checker. Checked 2026-10-01.
- ISJ reference format: https://purplelink.llc/format/references-for-isj/ - APA 6th edition per the Wiley author guidelines, with a DOI on every reference. Rules, three real examples, checker. Checked 2026-10-01.
- ICIS reference format: https://purplelink.llc/format/references-for-icis/ - APA 7th edition, alphabetical, inside a 16-page limit that includes references. Rules, examples, .bib checker. Checked 2026-10-01.
- HICSS reference format: https://purplelink.llc/format/references-for-hicss/ - APA, 7th edition preferred, alphabetical and unnumbered, inside a 10-page limit. Rules, three real examples, checker. Checked 2026-10-01.
- CHI reference format: https://purplelink.llc/format/references-for-chi/ - ACM Reference Format with acmart, single-column manuscript for review. BibTeX setup, three CHI examples, checker. Checked 2026-10-01.
- KDD reference format: https://purplelink.llc/format/references-for-kdd/ - ACM Reference Format with acmart sigconf. References sit outside the 8 content pages. BibTeX setup, examples. Checked 2026-10-01.
- WWW reference format: https://purplelink.llc/format/references-for-www/ - ACM Reference Format with acmart sigconf, 8 pages plus references up to 12. BibTeX setup, examples. Checked 2026-10-01.
- ICML reference format: https://purplelink.llc/format/references-for-icml/ - APA-style author-year with natbib and icml2026.bst. Setup lines, three examples run through the official .bst, checker. Checked 2026-10-01.
- ICLR reference format: https://purplelink.llc/format/references-for-iclr/ - natbib author-year with the iclr conference .bst from the official Master-Template. Setup, examples, page limits. Checked 2026-10-01.
- ACL reference format: https://purplelink.llc/format/references-for-acl/ - acl_natbib.bst with the acl style file, DOIs or Anthology links required. Setup, three ACL examples, checker. Checked 2026-10-01.
- AAAI reference format: https://purplelink.llc/format/references-for-aaai/ - aaai2027.bst, set by the style file, with natbib. 7 content pages plus 2 for references. Setup, examples, checker. Checked 2026-10-01.
- Springer LNCS reference format: https://purplelink.llc/format/references-for-springer-lncs/ - llncs.cls with splncs04.bst, numbered citations in square brackets. Setup lines, three LNCS examples, checker. Checked 2026-10-01.
- PLOS ONE reference format: https://purplelink.llc/format/references-for-plos-one/ - Vancouver style, numbered in order of appearance, first six authors then et al. plos2025.bst setup and examples. Checked 2026-10-01.
- Nature reference format: https://purplelink.llc/format/references-for-nature/ - numbered superscripts in order of citation, et al. after five authors, about 50 references. Rules, three examples, checker. Checked 2026-10-01.
- Science reference format: https://purplelink.llc/format/references-for-science/ - numbered in order of citation, italic numbers in parentheses, full author lists with no et al. Rules, examples, checker. Checked 2026-10-01.
- PNAS reference format: https://purplelink.llc/format/references-for-pnas/ - numbered in order of appearance, et al. after five authors, pnas-new.bst in the Overleaf template. Rules, examples, checker. Checked 2026-10-01.
- Tools hub: https://purplelink.llc/tools/

## Guides (free how-to articles)
- Guides index: https://purplelink.llc/guides/
- LaTeX hub: https://purplelink.llc/guides/latex/ — pillar page covering the full academic LaTeX workflow.
- BibTeX hub: https://purplelink.llc/guides/bibtex/ — pillar page covering bibliography management.
- Methodology problems peer reviewers flag, and how to fix them: https://purplelink.llc/guides/methodology-problems-peer-reviewers-flag/ — fifteen failure modes (p-hacking, HARKing, underpowered samples, test-train contamination, LLM self-judging, fabricated citations and more), each with a definition, an example, the fix and primary references.
- How to get feedback on a paper before submitting: https://purplelink.llc/guides/get-feedback-on-a-paper-before-submitting/ — colleagues, editing services, general AI assistants, preprints and Paper Review compared.
- AI paper review tools compared: https://purplelink.llc/guides/ai-paper-review-tools-compared/ — Paperpal Preflight, SciScore, Writefull, a general chatbot and Paper Review: what each checks, price, and what it misses.
- Best keyboard sound apps for Mac (2026): https://purplelink.llc/guides/best-keyboard-sound-apps-for-mac/ — Klack, KeyOpera, Thock, Mechvibes, Klakk, Snick, HapticPad and Keyfeel compared by price, sounds, permissions and what each does not do.
- Use Mechvibes sound packs on a Mac: https://purplelink.llc/guides/mechvibes-sound-packs-on-mac/ — classic and MechvibesDX packs, importing into Keyfeel, what does not carry over, and the Mac state of Mechvibes, MechvibesDX, Klack, Thock and KeyOpera.
- Is it safe to allow Full Disk Access, Input Monitoring or Accessibility on a Mac?: https://purplelink.llc/guides/mac-privacy-permissions-explained/ — what each permission allows, Apple's 2026-10-02 note on Full Disk Access, how to review and revoke them, and what Legroom, Keyfeel and Outbound Veil ask for.
- Best disk space analyzer and cleaner for Mac (2026): https://purplelink.llc/guides/best-disk-space-analyzer-for-mac/ — macOS Storage, DaisyDisk, GrandPerspective, OmniDiskSweeper, CleanMyMac, Hazel, Mole and more, plus what is safe to delete.
- Show free disk space in the Mac menu bar: https://purplelink.llc/guides/show-free-disk-space-mac-menu-bar/ — Finder, Storage settings, Disk Utility and df, then eight menu-bar apps (Legroom, Stats, iStat Menus, Mole, Mister Plimsoll and others) by price, low-space alerts, cleaning and macOS version.
- Best PII redaction tools for ChatGPT and AI chats (2026): https://purplelink.llc/guides/best-pii-redaction-tools-for-chatgpt/ — Outbound Veil, Predact, PrivacyScrubber, Presidio, ChatGPT's own controls and local models compared.
- Best software for tracking your research record (2026): https://purplelink.llc/guides/best-academic-record-tracking-software/ — Vitae, spreadsheets, Notion, Manuscripts, ORCID, Interfolio and more compared.
- How to track your academic CV and tenure case (2026): https://purplelink.llc/guides/track-academic-cv-tenure-case/ — 16 tools compared on cost and data ownership.
- Best Chrome extensions for Google Scholar (2026): https://purplelink.llc/guides/best-chrome-extensions-for-google-scholar/ — journal rankings, citation and author metrics, retraction warnings and what each cannot do.
- Overleaf alternatives for Mac: https://purplelink.llc/guides/overleaf-alternative-mac/ — offline LaTeX editors compared, and how to move a project off Overleaf.
- TeXShop alternative for Mac: https://purplelink.llc/guides/texshop-alternative-mac/ — ModernTex, TeXShop and TeXstudio compared on price, platforms, PDF sync, multi-file projects and bibliographies, with who should pick which.
- Best LaTeX editor for Mac in 2026: https://purplelink.llc/guides/best-mac-latex-editors/ — comparison of TeXShop, Texifier, Octree, VS Code, Overleaf, and ModernTex.
- GlobePin vs Polarsteps vs Visited: https://purplelink.llc/guides/globepin-vs-polarsteps/ — comparison of three iOS travel-mapping approaches.
- Best health tracking apps that keep your data on your phone (2026): https://purplelink.llc/guides/best-on-device-health-apps/ — about 30 iPhone health apps compared by App Store privacy label, account, where the data lives and price, with Haea (Purplelink's own, not yet released) disclosed.
- Convert a LaTeX paper to Word: https://purplelink.llc/guides/latex-to-word/ — step-by-step .tex → .docx for journal submission.
- Fix common BibTeX errors: https://purplelink.llc/guides/fix-bibtex-errors/ — diagnose and repair the most frequent .bib mistakes.
- IEEE vs APA vs MLA vs Chicago: https://purplelink.llc/guides/citation-styles-explained/ — how the four major citation styles differ and when to use each.
- Show changes between two LaTeX versions: https://purplelink.llc/guides/latex-track-changes/ — track changes in LaTeX with latexdiff.
- Count words in a LaTeX document: https://purplelink.llc/guides/latex-word-count/ — accurate word counts for .tex files.
- Get BibTeX from a DOI or arXiv ID: https://purplelink.llc/guides/doi-to-bibtex/ — fetch a clean BibTeX entry from an identifier.

## Focus Radio (free live music)
- Focus Radio: https://purplelink.llc/focus-radio/ — a free 24/7 live radio of original lofi chiptune for studying, coding and writing, with a built-in Pomodoro timer (25 minutes focus, 5 minutes break; a focus block starts at :00 and :30 past each hour, UTC). Instrumental, generated by an algorithm as it plays. Streams on the Purplelink YouTube channel.

## Blog (articles & updates)
- Blog index: https://purplelink.llc/blog/
- Starting Purplelink: https://purplelink.llc/blog/starting-purplelink/ - Why I formed a software LLC, what I'm building with it, and the philosophy behind making software that's...
- Why we built Haea on-device: https://purplelink.llc/blog/why-haea-is-on-device/ - Why Haea keeps all your health data on your iPhone - and why that decision shapes everything about how the...
- What GlobePin does that no other travel app does: https://purplelink.llc/blog/what-globepin-does-differently/ - Why GlobePin is different from every travel tracking app on the market - and what we built that the others...
- The LaTeX editor that academics actually want: https://purplelink.llc/blog/the-latex-editor-academics-want/ - Why existing LaTeX editors fail academic researchers - and what ModernTex does differently to serve the...
- Seven free LaTeX tools, right in your browser: https://purplelink.llc/blog/free-latex-tools/ - We launched free in-browser LaTeX tools: compile to PDF, convert to and from Word, diff versions, validate...