Something often overlooked is how your app integrates to the user's mobile experience. When listening to music and interacting with other apps, it can be a bad user experience for the user's audio experience to be cut off when your app has no use for a focused audio experience.

Here's a short code snippet to allow your user to play background music in your IOS App...

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:nil];