It seems there are some compatibility issues with iOS7. For example all of my purchased music that I have bought from iTunes appears when viewing by Artist and Albums, even when I set show iTunes Match items to ‘off’. The artist/song is visible but I can’t select it (it states All Tracks Filtered – Adjust Filtering above).
This wouldn’t be a large issue by itself but the app seems quite unstable now and crashes fairly often; for example if I go to the songs list and select the # icon so scroll to the end of the list, the app will crash. This is after two reinstalls of the app.
Is there an update planned to fix this? When it does work, the sound quality is noticeably better than Apple’s own inbuilt app!