Messenger currently has 900 million users, and Facebook says once you update you will see a "new phone icon" when in group conversations. Hitting the icon will start a phone call with everyone in the group.
The new addition gives Messenger nearly all the features of Skype, the only difference being that you need to have a Facebook account to use Messenger and not everyone cares to have one. Skype also offers group video chat, which we assume is Facebook's next logical update for Messenger.
Source:
FB
Written by: Andre Yoskowitz @ 23 Apr 2016 10:43