When the iPhone arrived in 2007, some thought that artist apps would be the future. So there was a gold rush followed by a lot of disappointment. They were expensive to build and hardly anyone used them. Even platforms like Mobile Roadie stepped away from music. Now they are back, Back, BACK in the shape of sponsored apps. Acts like Tiësto are, excuse the pun, testing the ground here and we look at what form these new apps will take as well as outline the dos and don’ts when a sponsor is involved in bankrolling the whole thing.