I highly recommend OneBit Adventure. It is available on mobile and Steam. The last time I checked it is still in active development, So you will see new features and improvements frequently.

Unhook - Remove YouTube Recommended Videos - This one simplifies the YouTube experience and helps you to spend less time watching videos endlessly.

The one I couldn't find mentioned here would be /c/digitalminimalism. Here we could share tips and experiences on reducing screen time, using dumbphones, exploring minimal apps, and all things related to simplifying our digital lives.