Turntable.fm, the website and web app that has caught on with Facebook users and other music lovers, is preparing a mobile version of the app for iOS devices, TechCrunch reports. The U.S.-only website allows visitors to select music and try out a DJ set in a virtual club, with points being awarded for songs participants like and links for them to buy them from iTunes. While playing a set, users can automatically post the songs they are playing or listenting to on Twitter and Facebook.