Hey Product Hunt! 👋

I’m Sulthan, and I built Ninuli as my submission for the RevenueCat Ship-a-ton.

If you're like me, your notes pile up and are rarely revisited. Without active review, we forget 80% of what we learn within a week. While AI flashcard apps exist, they force you to upload your personal notes to their servers.

I wanted a smarter way to study that didn't compromise my privacy. So, I built Ninuli: a completely offline, privacy-first spaced repetition app.

🧠 The Core Engine (Free Forever)
Ninuli is fully functional for casual learners at $0. The Free tier includes:

100% Offline AI Generation: Paste any text, and an on-device AI model drafts flashcards locally. Nothing is sent to a server.
SM-2 Spaced Repetition: The proven SuperMemo-2 algorithm calculates optimal review intervals.
Complete Import & Export Freedom: Seamlessly migrate your learning without platform lock-in. Full import and export support for:
- Anki Deck Package (.apkg)
- Notes in Plain Text (.txt)
- Cards in Plain Text (.txt)
Capacity: Up to 3 decks, 150 total cards, 50 daily reviews, and 2 AI generations per day.

⚡ Supercharging with Ninuli Pro
For power users and serious students, I integrated RevenueCat to build a robust Pro Tier ($3.99/month) that scales infinitely. Upgrading unlocks:

The FSRS 4.5 Algorithm: Switch to the cutting-edge Free Spaced Repetition Scheduler for highly optimized memory retention and fewer daily reviews.
Pro Analytics & Retention Curves: Visualize your learning with weekly review bar charts, memory stability stats, and FSRS 4.5 vs SM-2 memory retention projections R(t) = 0.9^{t/S}.
Zero-Knowledge Cloud Backup: Securely back up your database to your personal Google Drive. Data is AES-256 encrypted locally using a custom Vault Password before it leaves your phone.
Unlimited Scale: Up to 100 decks, unlimited cards, unlimited daily reviews, and 10 offline AI generations every day.

🎂 Birthday Special: 28 Days of Ninuli Pro

I turn 28 on September 10th! To celebrate shipping Ninuli and hitting another milestone year, I’m giving the Product Hunt community an extended 28-day free trial of Ninuli Pro.

How to claim it:

Tap Pro in the app.
At the Google Play payment sheet, tap your payment method and select Redeem code.
Enter code NNLBDAY28 at checkout. (Valid until September 16!)

I’d love for you to download it on Android, paste in some notes, and let the offline AI do the heavy lifting.

I'd appreciate feedback on:

The quality and speed of the on-device AI card generation on your phone.
How seamlessly the .apkg and .txt imports/exports fit into your existing note-taking and study workflow.
How you feel about the transition from SM-2 to FSRS 4.5 if you try the Pro tier.

Thank you for checking out Ninuli and celebrating my 28th with me! 🚀

100% Offline AI Generation: Paste any text, and an on-device AI model drafts flashcards locally. Nothing is sent to a server.
SM-2 Spaced Repetition: The proven SuperMemo-2 algorithm calculates optimal review intervals.
Complete Import & Export Freedom: Seamlessly migrate your learning without platform lock-in. Full import and export support for:
- Anki Deck Package (.apkg)
- Notes in Plain Text (.txt)
- Cards in Plain Text (.txt)
Capacity: Up to 3 decks, 150 total cards, 50 daily reviews, and 2 AI generations per day.