This app makes use of the built-in black and white device feature to provide a blue-light filtered screen without the use of an overlay screen, to help relax your eyes at night and disincentivise phone usage.
<img src="assets/get_fdroid.png" alt="Get it on F-Droid" height="90">
<img src="assets/get_playstore.png" alt="Get it on the Play Store" height="90">
Monochromatic needs the Write Secure Settings permission, which is normally unavailable to apps. However, you can grant this permission with the following ADB command:
adb shell pm grant uk.co.richyhbm.monochromatic android.permission.WRITE_SECURE_SETTINGS