Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
DUSK - Anonymous live video
Metastream - Watch streaming media with friends
Facebook Live Video and Collages - Show your friends what you’re seeing in real time
StreamParty - StreamParty is a watch communiry, that allows you to watch video streams in sync with the people you care about, on multiple services.
Periscope on Twitter for iOS - Stream live video inside your tweets