I have only one suggestion.

It is a great app, however I use the music player alot when Im working out. I have an arm holster... and while the swipe gesture is amazing in everything else... when it comes to jogging that whole thing SUCKS !!!
Its a bit difficult to change songs when you are having to jog and try to swipe fingers across the screen. So my thought was this and while it may not be possible I still want to throw it out there...

Is it possible for the Music player to have an option where instead of having the time on the lock screen it has an option that is live the whole time ( maybe a setting called workout mode) that lets you skip, pause, play, and go back... and have it as a horizontal selection ( skip fwd is on the bottom of screen, pause maybe at the right, play on the left, and back on the top. Pretty much to sum up all my rambling. If the music player can be in landscape mode and overriding the lock screen while jogging... with big buttons easy to see and touch while working out. If you can create let alone understand my ramblings I would gladly pay for this app. !

other than that... I absolutely love love love the app.