I used an old iphone in conjunction with the apple tv to stream to my whole house music system
Remove one picture frkm the frame and build your own holder for the device you choose to use.
Notch built frame to accomodate the charging cord and nicely fit the phone
Drill a hole that lines up with the power button and cut a small nail to length with pliers so you may still access the power button. Glue frame into picture frame to secure using hot glue.
I had a outlet on the other side of the wall so I popped a hole through to provide permanent power.
I hung the frame on the wall and added some velcro to secure tightly. I set it to stay on all of the time and even have it set as an alram through Pandora to play in the morning to wake up.