Fillwell — Last updated: August 7, 2026
Fillwell calculates a daily fluid and electrolyte target from your body weight, activity level and climate, then lets you log your bottle level and mineral intake with one tap. Your bottle fill visualization, mineral balance and history are all stored on your device. Nothing is uploaded, and there is no account to create.
Your body weight, activity level, climate setting, bottle logs, mineral (sodium/potassium/magnesium) entries and reminder settings are stored only on your device. Fillwell has no account system and uploads nothing. Deleting the app deletes the data.
We use Firebase Analytics for anonymized usage data (such as which screens are opened) and Sentry / Firebase Crashlytics for crash reports, so we can fix problems. Neither receives your weight, logs, or mineral entries, and neither identifies you.
The app integrates Google AdMob to display advertisements. AdMob may collect device identifiers to deliver and measure ads, in accordance with Google's privacy policy. On iOS we ask for your permission through Apple's App Tracking Transparency before any tracking. A one-time in-app purchase removes ads.
Fillwell is not directed to children under 13 and we do not knowingly collect personal information from children.
We may update this policy; changes are posted on this page.