I have some suggestions for the music app. I find the music app simple in a good sleek way. However I'd love a way to be able to click on an artist and pull up all songs on the device from that artist.
For example imagine you have your whole music library on shuffle and come across a song by a band you haven't listened to in ages. It would be handy if you could click the artists name and see/play all the music you have by that specific artist. This feature could also be used if your listening to a compilation album and decide to listen to all the songs from a specific artist.
Also I often listen to audio productions that can be 2 hours in length. Often closing the music app will mean that the audio file will be back at the start when I open it again later. A setting to resume where you left would be handy but also a kind of bookmarking feature would be great e.g. it marks where you left it so you can go right back to that place later on. You could even add an option so that it bookmarked it a few seconds earlier e.g. 30 seconds earlier so you don't miss anything