I just discovered this program and immediately installed and tried it out. I do not like the fact that backspace seems not to work correctly after when mistypin

I just discovered this program and immediately installed and tried it out. I do not like the fact that backspace seems not to work correctly after when mistyping a letter. It is strange as well having 2 spaces at the end of phrases. I would like a nice typing tutor program for the Unix console. Some months ago I discovered the program "Klavaro". It exists for Linux and Windows (and maybe others). I quite like its behavior when typing the text, including handling typing errors. Update: I just discovered, that I judged too quickly. The behavior seems to depend on lessons. For example in Lesson V19/3 there is text that you just overwrite. And when making errors you can come back with the backspace.