Audio playing while app in background iOS

Question

I have an app mostly based around Core Bluetooth. When something specific happens, the app is woken up using Core Bluetooth background modes and it fires off an alarm, however I

Answer 1

Apple has a nice Technical Q&A article about this in its documentation (see also Playing and Recording Background Audio).

I think one big thing missing is that you haven't activated the Audio Background Mode in the Xcode settings:

Maybe also adding [self.player prepareToPlay] in your alert method is helpful.