Metastream - Watch streaming media with friends
Movie Guessr - How well do you know your movie ratings?
Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
Tweedle App - Notion is nice but sometimes all you need is an app like Tweedle.
StreamParty - StreamParty is a watch communiry, that allows you to watch video streams in sync with the people you care about, on multiple services.
Tweeticide - Tweeticide – Delete All Tweets is a commercial app that enables you to delete all of your tweets at once.