Apple TV - New Apple TV running tvOS
Metastream - Watch streaming media with friends
Caavo - One search. One experience. One remote. All your content.
Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
NVIDIA Shield TV - Streaming box with Google Assistant and Google Cast.
Hyperbeam - A better way to watch together online