Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
Musicolet - Musicolet is a small yet feature-rich offline Music Player for Android.
Metastream - Watch streaming media with friends
Palco MP3 - Palco MP3 is the largest Brazilian application for independent artists and offers more than 1 million songs for you to listen and download on your mobile device.
StreamParty - StreamParty is a watch communiry, that allows you to watch video streams in sync with the people you care about, on multiple services.
Audiomack - The free SoundCloud alternative