All calls from Viber and Skype are appearing as normal calls after updating to iOS 10. How do I disable this?

After updating my iPhone 6 to iOS 10, all calls coming from Viber and Skype are appearing in the calls list as normal phone calls. Also, when I'm on a Viber call and a real phone call comes, I don't get notified. Before iOS 10 it used to mute Viber and give me a notification than someone is calling. How do I return back to these settings?

I don't think it is possible to revert back to old settings now. I have opened a ticket with apple to get the users freedom to either use or not use. The setting like Setting -> Phone -> Service provider makes perfect sense. Lets see if apple provides this capabilities or not.

EDIT: I messed up and this is an article from an ios10 preview version. This setting seems to not exist anymore. So as far as I know, reverting to the old way is not possible :/

This change is due to Viber and Skype now using CallKit which you can read up on here.

In that article it says this:

It’s important to note that Apple won’t force you to let any VoIP app integrate with Phone without your permission. Just like you must authorize third-party apps to access your camera or microphone, CallKit-enabled apps will put up a new type of iOS prompt at first run asking for permission to use CallKit.

Makes perfect sense in my eyes. A little further down they say this:

Any VoIP apps that you’ve permitted to use CallKit will honor your current Do Not Disturb setting and a list of blocked contacts. Lastly, you can revoke these permissions for VoIP apps by flipping switches in Settings → Phone → Service Providers.

So going to Service Providers and disabling access to CallKit should revert it back to the way you want.