In case you've forgotten about it, Periscope is Twitter's somewhat-unpopular streaming platform designed for use on iOS and Android devices. There haven't been any major feature additions in well over a year, but that changes today. Periscope users can now invite guests onto their streams, similar to what Instagram added in 2017.

Starting today, broadcasters can go live with guests and invite anyone to join. When guests request to join a stream, a button appears on the broadcaster's phone. Tapping the button will add the guest's video feed to the top-left corner, visible by anyone watching the broadcast.

Guests can only join if they have the Periscope app installed, but the ability to join directly from Twitter is being worked on. The company said in a blog post, "Whether you’re broadcasting or just listening in, things are about to get much more interesting. Stay tuned!"

Source: @Periscope (Medium), Periscope Help