Ebb

Ebb records your menstrual cycle, estimates when your next period is likely, and reminds you beforehand. It does all of that on your phone.

Your data stays on your phone

• No account, no server, no sync. Everything you log is kept in a database on your device.

• No internet permission. Android itself stops Ebb from sending anything anywhere, and you can check that in the app's permission list.

• No analytics, advertising or tracking, and excluded from Android's cloud backup.

• Delete everything in Settings whenever you like.

An estimate that's honest about what it knows

Ebb learns your rhythm from your own recent cycles and shows the next period as a range, with how sure it is. With little history it leans on a typical 28-day cycle and says so. Irregular cycles get a wider window, not false confidence. The method is plain arithmetic, explained in the app.

Forgiving when life happens

• Forgot to log? Add a period on an earlier day, or fill in past ones.

• A cycle thrown off by illness or a medication change can be left out of the estimate, with a note to remember why.

• If periods go unlogged for a while, the estimate carries on, says so, and History points out the gaps.

Reminders without the cloud

A heads-up before your period is expected, scheduled on the phone itself, so it arrives with no signal and in airplane mode.

Backups and new phones

Save your history to a plain, documented file wherever you choose, or move it to another phone by scanning a few QR codes: one phone shows, the other looks. Nothing goes over a network.

More than one person

Helping a child who's just starting? Track them too, switch with a tap, and hand their history over to their own phone when the time comes.

There's no cloud copy of your history, so a lost phone means lost history unless you've saved a backup file.

Ebb is free, open source under the MIT licence, and has no ads or premium tier.