The LA Phil has made a “conductor hero” app for the iPhone called Bravo Gustavo. It’s free, and surprisingly fun.
Right now, you get to conduct two movements from Berlioz’s Symphonie Fantastique. Expect more tunes to come in software updates.
In case anybody was wondering, this is the right way to create an iPhone app to promote an artist: come up with something simple and cool that’s related to what the performer does, give it away, and enjoy the exposure that results. You’re not going to make any money from it, so treat it as PR, not direct marketing.