I teach, and I've started using my personal iPad and the iPad that belongs to the school.
Normally, I use a lot of hands-on multisensory methods to teach students with special needs; however, I have one particular student that wasn't responding as well to my methods. I tried him on an iPad, and it was great. It was novel, but the apps would not allow him to do anything else with the virtual manipulatives than what he was supposed to do.
And I also let the other students take turns using them. I put them on an app that correlates to the IEP objective, and it is great drill-and-practice.