3ea090ae4b
Replace the NSSpellChecker + regex-stub engine with harper-core 2.5.0: real subject-verb agreement, verb forms, punctuation, repetition and spelling. New harper-ffi crate (staticlib) exposes harper_check over a C ABI; the CHarper module bridges it to Swift; HarperEngine maps Harper's char spans onto UTF-16 ranges and de-dups overlapping lints. NSSpellChecker stays only as a case-preserving spelling supplement, which fixes the problemm->Problem mis-casing. Bulk apply now skips no-op suggestions. build.sh / scripts/build.sh build the universal static lib; target/ and lib/ are gitignored (regenerate via harper-ffi/build.sh). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
✒️ GrammaGem
Write it once. Get it right.
The private, on-device writing assistant for Mac. Fix grammar, sharpen tone, and rewrite anything — in every app — for one payment, forever.
Stop renting your grammar checker.
Grammarly costs around $144 every year, reads everything you type, and sends it to their servers. GrammaGem does the same job — better — entirely on your Mac, for a single payment.
Select text in any app, press one hotkey, and it’s polished in place. No copy-paste, no switching windows, and nothing ever leaves your machine.
“One payment and it’s mine forever — such a bargain.” 👍
Why people switch
| Grammarly | GrammaGem | |
|---|---|---|
| Price | ~$144 / year, forever | Pay once |
| Your words | Sent to the cloud | Never leave your Mac |
| Works offline | ❌ | ✅ |
| Where it works | Where the extension reaches | Every app, system-wide |
| Speed | Round-trip to a server | Instant, on-device |
What you get
- ⚡ Instant corrections — grammar, spelling, punctuation, and clarity, fixed the moment you ask.
- 🔒 Private by design — everything runs on your Mac’s Neural Engine. Your writing is never uploaded, logged, or used to train a model.
- ⌨️ One global hotkey — fix or rewrite the selected text in any app: Mail, Slack, Notion, Chrome, Messages, VS Code, and more.
- ✨ Ask & rewrite — “make it shorter,” “more formal,” “translate to German” — done in place.
- 🎚️ Writing Modes — Email, Post, Team Chat, Academic, Code — switch the tone instantly, or let GrammaGem pick the right one for the app you’re in.
- 📖 Personal dictionary — teach it your names, brand terms, and jargon once; it stops “correcting” them forever.
- 🖥️ A clean management app — manage your devices, shortcuts, modes, and privacy from one tidy window.
Buy once. Write forever.
No subscription. No per-seat fees. One payment, lifetime updates.
| Plan | Price | Devices |
|---|---|---|
| Solo | $39 | 1 Mac |
| Personal ⭐ | $59 | 2 Macs |
| Studio | $89 | 4 Macs |
| Startup License | $159 | 10 Macs |
Apple Silicon · macOS 14+ · 14-day money-back guarantee, no questions asked.
FAQ
Is my writing really private? Yes. Every correction and rewrite runs on your Mac. Your text is never uploaded, logged, or used for training.
Do I need internet? No. Core features work fully offline.
Is this a subscription? No — it’s a one-time purchase with lifetime updates and a 14-day money-back guarantee.
What about plagiarism detection? GrammaGem is private-first, so it doesn’t do cloud plagiarism scanning — that would require sending your writing to a server. Everything else you’d expect is here.
Built in public
GrammaGem is open source under the MIT License. We believe a privacy tool should be one you can actually inspect. Issues and pull requests are welcome.
© 2026 FounderGem LLC · 1309 Coffeen Avenue STE 1200, Sheridan, WY 82801, USA