Searching for artful apps for my middle school Art Class

[just_another_dude]

I'm a middle school arts teacher and I'm trying to incorporate technology into my art program. Has anyone come across any cool musical iPhone Apps in iTunes App store? These days all the kids have smart phones, and I figured that’s a great tool to start with.
I found this one really cool App in the App store called “Picture Music”, it basically allows you take a picture with your iPhone, and then covert it into music, using any instrument of choice, which is a really cool concept and my students responded very well, taking interest in art for a change. So naturally I’m looking to keep this fire going
I would really appreciate any information on any other cool artful, musical or picture apps, that I might be able to introduce in my current and future classes.
Thanks!