Private cycle tracking on your device
Need help with Ondi? Email us at blueflamegames@proton.me.
When you log flow (not spotting) at least 3 days after your last period day, and at least two weeks into the current cycle, Ondi starts a new cycle and closes the previous one automatically. A missed day of logging in the middle of a period doesn't split it.
All data is stored on your device only. No accounts, no cloud, no servers. Deleting the app permanently deletes all data.
Predictions improve with more data. Ondi starts with a baseline and refines after 3-6 cycles.
Yes. Use the date selector in the daily log.
Compatible watches send wrist temperature via Apple Health for ovulation confirmation.
Period tracking, daily symptom logging, cycle forecasting, calendar, and irregularity notifications.
Everything is free for 7 days. After that, a one-time purchase unlocks fertility tracking, Trying to Conceive, pregnancy, postpartum and post-menopause modes, contraception side effect analysis, health pattern insights, migraine monitoring, and data export. No subscription.
Use "Delete All Data" in settings. This is permanent. No server deletion is needed because no data is stored on any server.