?? Is that an app or are you curious about openboard? It's a FOSS keyboard, better than thestock grapheme one.
Still having issues turning off suggestions/autocorrect tho
Discussion
Interesting.. I use it precisely because I like the corrections. They can be turned off in the settings tho
Simple Keyboard its also a good Foss keyboard with no autocorrect and it can be customized to any colors you want, might wanna give that a shot
https://www.f-droid.org/packages/com.simplemobiletools.keyboard/
Simple keyboard is the one for sure 🤙