Never one to miss a chance to make money through new technology, Soulja Boy Tell’Em is the latest artist to launch an iPhone app. He’s teamed up with developer Moderati for an app that lets fans remix three of his songs by muting or soloing individual elements while triggering seven samples.More interestingly, they can then share their versions via email or Facebook. “If you’re looking at our target demo, our consumer for music, I think kids are going to be more and more interested in doing something interactive,” says Christian Jorg, head of digital at Island Def Jam Music Group.We agree: the first wave of artist-focused iPhone apps were purely promotional, but more recent efforts have introduced a lot more interactivity. Remixing is a popular theme – trance star BT recently launched his own Sonifi app, while David Bowie will soon launch one allowing fans to twiddle about with Space Oddity.