https://techcrunch.com/2018/06/04/apple-is-adding-group-facetime-video-calls-to-ios-12/

Apple is adding the ability to FaceTime more people onto a video call, allowing more than a dozen people to be on the call — and tapping an increasing interest in group video calling stemming from apps like Houseparty

As far as features go, this was a pretty natural addition to the FaceTime App. Houseparty exposed a lot of interest in this area, allowing multiple friends to spin up a video chat. But it’s also a technically strenuous proposition running multiple livestreams, and Apple does seem uniquely positioned to absorb the technical overhead (and costs) of running multiple FaceTime streams all at once. Houseparty allows up to 8 people streaming in a video call at once, though the last significant update we might have heard from Houseparty was some tweaks to notifications in January last year. Houseparty said it had 1 million users in November 2016.