The short version: your hydration data stays on your phone. Hydrate has no accounts, no sign-up, no ads, and no tracking. The only thing that ever leaves your device is anonymous usage analytics — and you can turn that off.
Your drink logs, daily goal, reminder settings, streaks, drops, awards, quests and Dewy's outfit are stored only on your device (and in the app's local App Group container so the Lock Screen features can work). I never see this data and it is never uploaded anywhere. You can erase all of it at any time in Settings → Data → Reset all data, or by deleting the app.
Hydrate uses Google Firebase Analytics to understand which features get used so I can improve the app. This includes: screen views, feature-usage events (for example "a drink was logged", its type and amount), and coarse app settings (like your goal size and reminder interval). It is keyed to a random per-install identifier — not your name, email, phone number or location, none of which the app ever asks for.
Reminders are local notifications, scheduled and delivered entirely on your device — there is no push server. The Lock Screen / Dynamic Island Live Activity is rendered on-device from your local data.
Hydrate is not directed at children under 13 and knowingly collects no personal information from anyone, including children.
If this policy changes, the new version will be posted at this address with an updated effective date. Material changes will be called out in the app's release notes.
Questions about privacy? Email faisalarip10@gmail.com.