this app has been SO useful for me. in the story section, you can click on words you don't know to look up the definition, origin, pronunciation, etc. personally, I love the writing feature. you can also group words into dif difficulties and practice per category. one thing, though, and it's that my screen keeps going white, in which I would have to close and reopen the app. this app is great for people like me who wants to learn Mandarin, I hope they fix this bug to make the app even better xx