A period calendar that stays yours
Track your cycle in a calm, simple calendar. Every feature is free, and your data never leaves your phone — no account, no server, fully offline.
Get it on Google Play



Every feature free
Cycle prediction, ovulation and fertile window, PMS days, home-screen widgets, reminders and statistics — all included, no subscription, no locked features.
100% on your device
No account, no sign-up, no server. Your cycle data is stored only on your phone and the app works completely offline.
Calm, discreet design
No pink flowers, no baby talk. A quiet, neutral calendar in cream and clay that looks like any other app on your home screen.
A calendar, not a chore
Mark a period in one tap. Peridot learns your cycle and quietly shows predictions, ovulation and PMS days ahead of time.
FAQ
- Is Peridot really free?
- Yes. Every feature — prediction, ovulation, PMS days, widgets, reminders, statistics — is free. There is no subscription and nothing is locked behind a paywall.
- Where is my data stored?
- Only on your phone. Peridot has no account system and no server, and it works fully offline. Nothing is uploaded anywhere.
- How accurate are the predictions?
- Predictions are based on your own logged cycles and get better as you log more. They are estimates for planning, not medical advice or contraception.
- What happens if I change phones?
- Because data lives only on your device, you can export a local backup file and import it on your new phone.