Togetherly - Watch Youtube with friends
Grabyo - Stream, edit and publish video anywhere, anytime
ShareTube - Watch YouTube, synced with friends.
VIXY video - Your videos online, the smart way
Showgoers - Showgoers is a website dedicated to watching Netflix movies together with friends or loved ones who are not sitting on the same PC.
Quik by GoPro - Easiest way to create awesome videos