Suggestions (but they are not so bad, so only 1 star deduction):
- In the parent / Gehemmenü only the maximum volume should be set, the child should the volume yet still be able to regulate itself a bit (eg in bed quietly, in the car louder)
- The display should support more than 8 characters, so long audiobook titles are displayed properly (currently the title is choppy cryptic, as in the old Windows)
- The Playlists / Albums should not be in the secret menu, but can be operated from the child, so that it can choose an audio book itself.