Who else thinks that sololearn should add undo and redo button

Answer 1

Good idea. Until then on an Android phone you can install Hacker's Keyboard. Then undo works by using Ctrl-z, just like on a PC. You can also use Ctrl-x to cut, Ctrl-c to copy and Ctrl-v to paste.

Answer 2

Suggest on [e-mail]

Answer 3

also Samsung keyboard app has undo (android), and clipboard