Greyscale

Quickly switch grayscale mode for Super AMOLED to save power.

Before using this Application, you need to use "adb tools" to grant permission, copy below command and exec it on a PC.

adb shell pm grant com.fei_ke.greyscale android.permission.WRITE_SECURE_SETTINGS

About "adb tools": https://www.xda-developers.com/install-adb-windows-macos-linux/

Source code: https://github.com/fei-ke/Greyscale