I don't think that I am "good" at all, I've only even known about it for about a week! I just sort of got obsessed, though.
And found ways to practice while driving around town.
I'm stuck on that grade 6 though, I can't figure out how to move that quickly. I think I've hit a wall on that app. I don't know if it expects you to move to mental math there or not. I can do every problem in grade 6 (finally figured out what I was doing wrong with multiplication and division), but I just can't do it that fast! I'm not sure what the intent was with the app. But it has been quite helpful for me so far.
Maybe I should start a post for adults learning the Soroban.