I meant OLED burn in specifically but I suppose a screensaver would technically work, although I prefer the pixel shift hack available on some devices. Does stuff like draw status bar icons with a dithering pattern and swaps the on pixels with their off neighbors. Dunno if it actually works as intended though. The phone that had it got destroyed.
Gobble gobble (mander.xyz)
Whatever, I'll use it and abuse it. (lazysoci.al)