Beta

Join the beta.

Play Lemma on TestFlight for two weeks before launch on 31 October 2026, on iPhone or iPad, and tell us what to fix.

What to test

• The daily lemma, from the first cell to the Proven screen.
• Hints: do they explain the move in words you understand?
• Circles: invite someone, prove the same lemma, compare times.
• Reminders: do they arrive when you asked for them?
• Lemma Plus, in the sandbox, at no charge: corollaries and the archive.

How to join

Write to us from the iPhone or iPad you want to play on. We reply with a TestFlight invitation; tap it, then tap Install.

You need an iPhone or iPad on iOS 18 or later. The beta is free and ends at launch. We keep very little about you; see the privacy policy.