Regarding the play/pause FOR RESI...the older Crestron app for Android (not Go) supported notification widget buttons. It was so convinient there, I had play/pause, prev/next and volume contol, 6 buttons I believe. The app didn't have to be in the foreground for this to work.

 

Now that iOS supports widgets, I wonder if there is automation app that you can create custom widget with a few buttons, and simply have a UDP packet sent to crestron. Programmatically/SIMPL change what source/room the widget control, based on last selection in the Crestron app for that IPID.