The content of the whole German is so weak! I have finished all of them, until the end of B2, and the total words (weak words, medium words, learned words) are not even 1100 in total which is not the case in real German learning, normally someone who finishes A2, should know more than 2000 words but within the app, even if you finish B2, the total number of the words you learn is around 1050, Grammer content is also weak! App works very stable, i don't have problem with that but words not enough