We reported on the beta launch of iPhone social music app Clerkd last year (Bulletin, 17-Dec-12), but now it’s launching officially. It’s good timing too, since the app includes many of the features that people are expecting to be included in Twitter’s about-to-launch music app. Clerkd is essentially a way for people to play music – both the songs stored on their iPhone and tunes drawn from Spotify, SoundCloud and Jamendo – with their listening habits shared to friends’ feeds within the app for conversation and recommendations. Locations are tagged too. Clerkd says it redesigned the app during the beta-testing period to make it easier to use, with plans to connect in more music services and launch web/Android versions of the app in the coming months.