Metastream - Watch streaming media with friends
Voicegram by Sayspring - Record and share conversations with Alexa from the browser
Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
Otter - Remember, search, and share your voice conversations
StreamParty - StreamParty is a watch communiry, that allows you to watch video streams in sync with the people you care about, on multiple services.
Chhirp - A mic button for Twitter