Trakt.tv - Automatically track TV shows & movies you're watching.

Netflix Party - Netflix Party is an extension for watching Netflix remotely with friends and family for movies nights with that long-distance special someone.

Simkl - Simkl is a TV, anime, and movie tracker that keeps a history of all the shows and movies you watch in one, central location. It’s a mobile app, a website, Google Chrome extension to keep track of everything you watch and integrates with many TV apps

Hyperbeam - A better way to watch together online

Showly OSS - Showly is modern, slick, open source Android TV Shows Tracker. This fork gets rid of all proprietary tracking libraries.

Metastream - Watch streaming media with friends