Show HN: I built a free AI study tool– paste notes, get flashcards in 10 seconds (opens in new tab)

Hey HN, I built a free AI flashcard generator with no signup and no paywall. Quizlet charges $7.99/month, Revisely caps free users at 3 generations, Knowt keeps moving features behind paywalls. I wanted to build the opposite of that. https://prepareyourself.app Paste text or upload a PDF. Pick an output type — flashcards, quiz, summary, or explain-with-examples. Get results in ~10 seconds. Done. I've been running it for 28 days. Here are the real numbers:

- 180 users. 8 of them engaged deeply. One person hit "review again" 64 times on a single flashcard deck. The other 172 bounced.

- Indian users spend 2x longer than US users (96 sec vs 44 sec). Bengaluru and Ahmedabad are my strongest cities. No idea why.

- Flashcards get 10x the engagement of quizzes. Quiz completions in a month: 1 person. So I made flashcards the default.

- Day 7 retention: 0%. Literally zero. Just shipped spaced repetition reminders — no data yet on whether it helps.

- Revenue: $0.

So the product works for the few who try it. The problem is getting people to try it.

Features: 4 output types (flashcards, quiz, summary, explain-with-examples), PDF upload, TTS audio on every card, spaced repetition, export to PDF/DOCX/JSON, 11 languages. History and streaks stored client-side in IndexedDB — nothing leaves the browser unless you hit generate.

Stack: Next.js, Supabase, Claude Haiku, Vercel. No auth required — rate limiting via IP + fingerprinting.

Would love feedback on UX, output quality, or whether "free forever, no signup" is a viable positioning against VC-funded competitors who are all moving toward paywalls.

thank you!