Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
TogetherJS - TogetherJS is a platform designed by the Mozilla Labs with the feature of real-time collaboration for websites and even applications in addition to watching movies and videos together.
DJ Clique - Listen or watch your favourite content via Youtube on repeat, shuffle or synchronized on all your computers at the same time. Take turns DJ'ing. Enjoy private or public rooms by yourself or together with your friends in sync.
Juicebox.dj - Watch YouTube and discover music online with others.
TwoSeven - Web application that enables people to watch the same thing at the same time across the globe while...
Sync Video - Ever wanted to watch a video on YouTube or Vimeo simultaneously with your friends, who are not exactly sitting next to you? Now you can watch videos synchronized!