AmpMe app works simply enough. One person in a group gets to be the “host,” and when she starts a listening session the app provides a four-digit code. Anyone who wants to add their phone or tablet to the mix just can type that code into their own app, and the host’s phone will emit a high-frequency sound that syncs the music being played. There’s no Bluetooth involved, and the devices don’t have to be on the same network — they all just have enough of a connection to stream the music. The host is the only one that gets to choose the music, also it has been informed that AmpMe only works with SoundCloud.