Third Arm
Your central hub for notes, reminders, subscriptions, diary, study timers, flashcards, and more. Quick capture from the menu bar. Optional AI assistance. All in one app.
Download for Mac →One app for your everyday capture needs
Collect, organize, and manage your personal information across multiple categories. No more switching between apps.
Quick Notes
Capture ideas instantly. Quick notes sync across devices and support optional reminders.
Diary
Journal entries with optional titles. Keep your thoughts organized and searchable.
Reminders
Set reminders in hours, days, weeks, months, or fixed dates. Never miss a deadline.
Subscriptions
Track recurring subscriptions with due dates. Monthly, yearly, or custom durations.
Payments
Log one-off payments. Simple title and amount tracking for your spending.
Study Timers
Focus sessions with General or Focus Time modes. Unlimited timers—never counted toward your cap.
Flash Cards
Create and organize flashcards by category. Study smarter with AI-generated cards from existing content (Pro).
Images Pro
Store images locally with metadata. JPG, PNG, HEIC, GIF, WebP, BMP, TIFF.
Built for quick access
Menu Bar Quick-Add
Click the menu bar icon to add any entry type—Reminder, Timer, Subscription, Diary, Flash Card, or Payment—without ever opening the app. Pro users get Quick AI Assistant to add from natural language. Plus a built-in currency converter.
Calendar View
See subscription due dates and reminders on a monthly calendar. Click any day for a popover with everything due that day.
Sync
Real-time sync enabled by default. Your data stays in sync across devices. Offline queue captures entries when you're offline—they sync automatically when you're back.
Notifications
Local reminders for quick notes, study timer end, and due dates. Subscription renewal alerts (1, 3, or 5 days before). Optional dock badge count.
AI Assistant Pro
Ask questions about your data, add entries via natural language, generate flashcards. Powered by Gemini.
Summary & Insights Pro
Dashboard with insights across all your data. See your activity at a glance.
Choose your plan
Start free. Upgrade when you need more. Study timers are unlimited on all plans. Terms of Service · Privacy Policy
Free
Free
- 50 entries total
- Quick Notes, Diary, Reminders
- Subscriptions, Payments
- Study Timers (unlimited)
- Flash Cards
- Calendar view
- Sync across devices
- Menu bar quick-add
Pro
$3.99/month
- 500 entries
- Everything in Free
- Summary & Insights dashboard
- Images category
- AI assistant to generate, edit, delete any app content, or for quick assistance with anything
- ~3000 simple tasks/requests by AI assistant
- Animated backgrounds
- Permanent 120 entries after cancelling
Pro+
$9.99/month
- 5,000 entries
- Everything in Pro
- ~6000 simple tasks/requests by AI assistant
- Permanent 200 entries after cancelling
Simple from the start
Download, sign in, and start capturing. Your data syncs automatically.
Download & sign in
Get Third Arm from the Mac App Store. Sign in with Email, Apple, or Google. Sync is enabled by default—your data stays backed up and available everywhere.
Quick capture from the menu bar
Click the menu bar icon to add entries without opening the app. New reminder, timer, subscription, diary entry, flash card, or payment—or use Quick AI Assistant (Pro) to add from natural language.
Organize across categories
Use the collapsible sidebar to jump between Diary, Quick Notes, Reminders, Subscriptions, Payments, Study Timers, and Flash Cards. Everything in one place.
Optional: upgrade for AI & more
Pro unlocks the AI assistant, Summary dashboard, Images, and animated backgrounds. Pro+ offers higher limits. Restore purchases anytime in Settings.