Works well technically and the exercises so far have been good, but there's no option to fully mute the app. If I just want to expand my vocabulary and listen to music at the same time, it messes with the volume. An annoying feature. Also, speaking and hearing exercises have been turned off, and it still pushes those. Latest update changes the keyboard automatically, which is very annoying. If I want to use the layout for that language, I'll change it when I start doing duolingos.