I'm looking for an SIP client for iOS that supports CallKit - a new iOS 10 API that allows VoIP apps to blend into the OS and behave like the native Phone app (answer directly from the lockscreen, etc). License doesn't matter and I am happy to put good money into it if the app is worth the price.
My current app Bria (which is great if we ignore this issue) doesn't look very enthusiastic about supporting this so I am looking for an alternative.
