What is 'Test Out'?
I just tried this. It seems to be a series of questions and you get 20 xp if you get 20 or so right before getting 3 wrong. I've never seen this before, but I may have just missed it.
This is in the Android app, when you open a skill you have not completed, in the top right.
Basically, if you think you know the words you haven't yet learned in that skill, you can test out and see if you know them.
Ok, thanks. I did notice that I had to guess a few, so that makes sense.