I am not sure how to make it an Android screensaver because I am a Linux developer, I just ported it because SDL2 supports Android. And I think people nowadays don't use screensaver on Android.

I suggest to use it just as a clock with your old, unused Android phone, because they should be LCD screen. Please don't use it for long time on OLED screen (which is in most of new phones), because OLED screen will have scars if you display similar patterns for long time.

Display a flip clock on your phone. Requires no sensitive permission, double tap to switch between 12/24-hour clock format, rotate to switch between landscape and portrait.

Open source repo: https://github.com/AlynxZhou/flipclock-android/