Youtube Detox - Distraction-free Youtube search
Trakt.tv - Automatically track TV shows & movies you're watching.
YouTube Realtime - The true subscriber count for YouTube, with comparison too.
TV Time - TVShow Time is the place to track and watch your favorite TV shows and movies
YouTube Messenger - YouTube in-app video sharing and messaging
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