This app constantly breaks. It can be helpful when it works, but it constantly crashes, freezes, and sometimes just stops working in the oddest ways. The comments section only opens about half the time (the other half, it crashes the whole app restarting my lesson). It loves to crash on the last question of a lesson so I have to do it over (regardless of hearts lost). It doesn't always like to award you achievements: just got demoted from diamond and haven't unlocked the pearl league achievement