Introducing Sona
Simple to use, powerful underneath — FSRS-driven spaced repetition that tells you exactly what to review, and when.
Most flashcard apps make you choose: easy to use, or smart about when you should review a card. The smart ones tend to mean wrestling with decks, add-ons, and settings that assume you already know what FSRS is.
Sona is our attempt to not make you choose.
What Sona actually does
Every card you study is scheduled with FSRS, a modern, open spaced-repetition algorithm. You don't configure intervals or ease factors — you rate how a card went, and Sona figures out when you'll need to see it again.
On top of that scheduling core, Sona adds a few things we think are worth having from day one:
- AI card generation. Turn a PDF, a slide deck, a photo of your notes, a short topic description, or even a recorded lecture into a finished deck.
- Quiz modes. Multiple choice, true/false, written answer, listening, matching, and more — the same cards, reviewed a different way.
- Offline-first. Download a deck and study it, browse it, or quiz yourself on it with no connection at all. Your answers sync the moment you're back online.
- Deck sharing. Publish a deck publicly, or share it with specific people. Anyone can fork it into their own account and make it theirs.
Free means free
FSRS scheduling, every quiz mode, Browse mode, offline access, and syncing across your devices are unlimited on the Free plan — we don't think studying should have a paywall. Pro exists for the features that carry real ongoing infrastructure cost: AI generation, audio transcription, spoken-word playback of your cards, and extra storage for the media you embed in them.
What's next
This blog is where we'll post release notes and, when we have something useful to say, practical guidance on getting more out of spaced repetition. If you're new here — welcome. If you've been reviewing with Sona already, thank you for being early.