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 can recommend AnySoftKeyboard, it’s FOSS and very customizable. If you swipe up from the space bar, you get additional options.