Mobile (android) 3rd lesson (letters 3) 2nd part broke
I can't get past this point because once it gets to tap the pairs it gets stuck on du. When there are only two options left, du and its matching character, they are highlighted as incorrect.
I am having the same problem and have reported it in bugs. I got passed those lessons by using the desktop version which doesn't seem to have the problem, only to find that the same bug exists with the letter for ru. I keep going back to the desktop version to get through those lessons but would rather be able to just work on my phone. FYI, I also am using an android device.