With the release of iOS 10, iPhone owners got a really convenient opportunity, allowing to make VoIP calls without launching alternative instant messengers.
All you need to know about free calls through the application «Phone» on the iPhone read in this material.
Run the application (Skype, Viber, Whatsapp or any other), find the contact of interest, select the call option and only then make the call — You can forget about all these complex actions with the arrival of iOS 10. Now any call looks like this, as if using an application «Phone».
Any Skype Call, Viber, WhatsApp and so on is displayed on the locked screen as a normal call. And when talking via a VoIP service on a 3G network or Wi-Fi, any incoming classic call (from the mobile operator’s network) does not interrupt the current connection, as it was in iOS 9.
After installing and activating any VoIP messenger, run the application «Phone» and go to the contact card. Make a long click (press and hold) on any audio or video call icon located under the contact thumbnail.
Call options are displayed at the bottom, including via third-party messenger.
The call history under the contact will not show the call from the iPhone, already via VoIP messenger. By the way, skype number, Viber, Whatsapp and t.P. can be set by default.
And it will not be superfluous to make contact in the widget «Favorites», accessible from the lock screen. All contacts from the corresponding tab of the application will be displayed there «Phone». Read more about this here.