The definitions are good and also formated well. However, there are some serious problems. The main problem seems to be the smallness of the dictionary. The first three words I looked up as a test were not found: Gobelin, Täfelung, ruchbar.
Close matches don't seem to be shown. The options screen crashes. The app is only formatted for the original aspect ratio (not the new taller displays). Finally, the information screen seems to have been translated by machine (this is the least serioua problem).
If you have a small German vocabulary, this will probably be useful. Otherwise, steer clear.