This app is really interesting because it is part music player part instant messenger.
On Soundwave, you can create private group chats to share songs from any music app with your friends. It works great with Spotify, Rdio, etc!
The collection of songs that you've shared become a fun collection within your group of friends :)
Thanks to their latest update, you can now tap on any song to reveal a history of who else has been listening to it, helping you find musical soulmates.
You can follow other users to see their activity in a feed as they listen to music. Usually, you’ll receive an instant 30-second preview of songs that other people are listening to. Then you can tap on the song to browse related content on YouTube and SoundCloud!