I am currently working on the iOS application with VoIP features. I use CallKit to receive calls. When the device is locked and user accepts a call, the system UI appears and user can tap my application icon to move further to my app. That is an expected behavior and it works fine.
However, I have noticed that when you make a video call with Viber, the behavior is slightly different. When you accept a call, the system UI appears for a brief moment and then the Viber application appears automatically. That is not the case with Telegram, you still have to tap Telegram icon to move further. So the Viber behavior is not expected. Looks like guys from Viber somehow bypass the system UI and jump to their application directly.
Does anybody know how they did it?