What is this forked from?

[sm4rk0]

Hi! Great keybaord! Found it in F-droid, as a newly listed/recently updated app. Was wondering which Java keyboard you started with, as there's this line in initial commit:

KOTLIN MIGRATION SETUP: Converted Java keyboard to modern Kotlin architecture

[tribixbite]

Thanks!
See the README
Or the 9th line in the commit you linked :)