Social music service Soundrop has one of the most popular Spotify apps, offering virtual listening rooms (aka Turntable.fm without the avatars). More than 300m tracks have been played within its Spotify app, with listeners spending an average of three hours per session using it. Now the company is looking to take the idea back out beyond Spotify by working with developers and labels. Evolver.fm reports on Soundrop’s plans to launch a software development kit (SDK) for developers to create listening rooms that can appear elsewhere on the web – on artists’ own websites for example. Some clients are already working with the SDK, although Soundrop isn’t saying who just yet. As Turntable.fm’s initial momentum has waned – down to 60k monthly active users logging in with their Facebook accounts – so Soundrop has picked up the baton of real-time social listening.