Last updated: July 2026
We don't run servers, and we don't want your data.
Your learning progress, streak and settings are stored on your iPhone and, if you are signed into iCloud, backed up to your own private iCloud account so a new phone or a reinstall doesn't wipe your streak. That backup belongs to you — it sits in your iCloud, not ours, and we cannot read it. We operate no servers and require no account.
The free version shows an optional rewarded ad you can watch to unlock an extra session. Ads are served by Google AdMob, which is a third party with its own privacy policy. We request non-personalised ads only, so AdMob is not asked to build an advertising profile of you, and Fifteen does not ask for permission to track you across other apps.
If you are in the EU, UK or Switzerland, a consent form from Google appears before any ad loads, and your choice is stored by Google. You can change it at any time from Settings inside the app.
Fifteen Pro removes ads entirely.
If the app crashes, an anonymous crash report is sent to Sentry so we can fix it. It contains the error and the device model and iOS version — no name, no email, no learning data, and nothing that identifies you.
In-app purchases are processed by Apple, with subscription status managed through RevenueCat. We never see your payment details.
Daily reminders are scheduled locally on your device. Nothing is sent to us.
"Reset all progress" in the You tab clears everything on the device and in your iCloud backup. Deleting the app removes the rest.
Google AdMob (ads), Sentry (crash reports) and RevenueCat (purchases). Apple and iCloud handle the rest.
If this policy changes, the hosted version and the copy inside the app are updated together.