Fasting app notifications not working on Android
Short answer: most missed fasting alerts on Android come from three settings: notifications turned off for the app, battery optimization putting the app to sleep, or alarms and reminders permission turned off. Fix all three and alerts arrive on time.
1. Allow notifications
Settings → Apps → your fasting app → Notifications → allow. On Android 13 and later the app must ask first; if you tapped "Don't allow", turn it on here.
2. Turn off battery optimization
- Pixel and most phones: Settings → Apps → the app → App battery usage → Unrestricted.
- Samsung: Settings → Battery → Background usage limits → remove the app from Sleeping / Deep sleeping apps, and set App battery to Unrestricted.
- Xiaomi, Oppo, others: look for Autostart and Battery saver in the app's settings and allow both.
3. Allow alarms and reminders
Settings → Apps → Special app access → Alarms & reminders → allow the app. Without it, Android may delay the exact time an alert fires.
4. Check Do Not Disturb
Do Not Disturb or a bedtime mode can silence alerts. Add the app as an exception if you want the end-of-fast reminder.
A backup you can see
Fastrail can show progress in the status bar and on a home screen widget, so you know how long you have fasted even if an alert is silenced. Its reminder comes 1 hour before the end and when you reach your goal.