Lookup and learn: the German app from the hep verlag
The app is based on the teaching tool "clear voice." By Alex Bieli. It contains the grammatical terms and definitions in the glossary. These can be learned with digital flashcards. Using in-app purchase around 250 exercises also can be enabled, which you repeat important topics of the German language, such as word teaching, spelling, syntax, punctuation and style in many ways and deepen.