Privacy that is real, not marketing

Claims you can check

Most health apps ask you to trust a privacy policy. Cephalo is built so you can check the claims yourself: each one below comes with a way to verify it.

No account required

Start using the app immediately. No email, no sign-up, no personal information needed.

Check it: the App Store privacy label lists what the app collects.

Works fully offline

The app is fully functional without internet. Your headache data is never uploaded to us; all insights are computed on your device.

Check it: turn on airplane mode and the diary keeps working.

Your device, your data

All data is stored locally on your device. Export, delete, or transfer it anytime you want.

Check it: export or delete all of it, any time, from inside the app.

Optional iCloud sync

If you choose to sync, data is encrypted and stored only in your personal iCloud account.

Private federated learning

Better insights, learned together, without anyone's diary ever leaving their device. Off by default, entirely optional.

If you opt in, your phone briefly trains a small pattern model locally, using your own diary. Your entries, notes, and health data never leave your device.

The only thing shared is a short list of numbers describing general patterns, with random statistical noise added first, so your personal patterns can't be reconstructed.

Every contribution is encrypted so that it can only be decrypted merged with those of many other users. No one, including us, even in the event of a server breach, can see an individual contribution.

The combined result is an improved pattern model that every participant receives in return. You can opt out or delete your local participation data at any time, and the app works exactly the same if you never join.

The fine print

The privacy policy spells all of this out, including the minimal first-party reliability statistics the app sends: installs and sessions, never your entries.