cross-posted from: https://lemmy.ml/post/21015575
Hackers Keyboard has that via ctrl+z, but only in horizontal mode. For this only i had my Galaxy S3 in horizontal per default. But can’t do that with modern phones’ aspect ratio and i’m missing undo since then.
I’m using FlorisBoard: https://f-droid.org/packages/dev.patrickgold.florisboard/
Many people also like HeliBoard, which is somewhat simpler: https://f-droid.org/packages/helium314.keyboard/