Android's built-in battery saver can be set quite finely. However, it is not configurable out of the box. SaverTuner allows you to take advantage of this built-in battery saver. You can now set different profiles that save the battery more or less aggressively. From a daily optimization that does not affect performance to an extreme optimization that saves power as much as possible.
This application is based on Buoy. It adds support for Android 12+, save and restore profiles and improves the settings tiles.
Features
It uses hidden Android settings to specify custom behavior for the built in battery saver. Features include the following toggles:
Advertising to other apps that low power mode is enabled
Android's data saver for metered WiFi or mobile data connections
The built-in dark mode
Launch boost to accelerate app starts
Vibration
Showing window and activity animations
Allowing apps to use the SoundTrigger HAL
Deferring full device backups for later
Deferring app setting backups for later
Using the built-in web firewall to protect against possibly malicious sites
Changing the location access mode restrictions for apps
Reducing the max brightness of the panel
Forcing all apps into standby mode
Forcing all apps to not check data in the background
Disabling unnecessary sensors
Using the Always-On-Display
Putting the device into deep sleep as soon as the screen turns off
Sticky Low Power
It also enables something called "sticky" low power mode. Usually, when the device is plugged in and unplugged, the low power mode is then disabled. However, sticky mode re-applies low power mode afterwards to continue saving battery.
Disclaimers
Note that this app requires the WRITE_SECURE_SETTINGS permission that can be granted with EITHER a PC using ADB or root. Root is NOT required for this app, it is optional. Android 8.0+ is supported, with more features enabled on Android 10+.
The command to grant the permission is:
adb shell pm grant s1m.savertuner android.permission.WRITE_SECURE_SETTINGS
Uninstalling the app will not reset the battery saver configuration. You must set the Default profile to undo all changes before uninstalling.