iOS 10: How to show incoming VOIP call notification when app is in background?

Question

I\'m working on audio/video call and trying to get incoming call notification loop for 1 minute like WhatsApp shows in iOS when app is

Answer 1

iOS 10 CallKit is much better, no more notification but system call UI, just like the native call. There are some sample codes at Github, which are easier to read than apple's Speakerbox sample.