Speakerbox: Using CallKit to create a VoIP app

Last Revision:
Version 2.0, 2017-10-26
Update for Swift 4 and iOS 11.0.
(Full Revision History)
Build Requirements:
Xcode 9.0 or later; iOS 11.0 SDK or later
Runtime Requirements:
iOS 11.0 or later

This sample app demonstrates how to use CallKit framework in a VoIP app to allow it to integrate natively into the system.