FairBattery

The app notifies you as soon as the battery has reached a charge level of 80 % as a result of the charging process.

How to use:

1. When battery charge is lower than 80%, connect power.
2. Once the battery is charged 80%, an alarm notification will sound.
3. Then disconnect power or acknowledge the alarm notification.
4. Note: for subsequent alerts you need to disconnect power

That's literally it.