App Restrictions on iPod

Hello!

I'm using around 30 iPods for my company's app, however the app can close and staff can access the internal apps. I was wondering if there was a way to either stop the apps closing like the iPads in the apple stores or if there is a way to stop the internal apps eg PhotoBooth, music from opening (I still need access to the camera) I have tried the internal restrictions but they don't do what I need.

Regards

Jack