we've seen that several students installed the tutu-app.
This is like a black-market appstore. They can download it and install it from several websites, and it does not require an apple-ID.
We have blocked all the websites we could find that had this download available. But not sure how we're supposed to catch the ones who allready has it, or stop people from sending the file to their iPad via email.
If it was an appstore-app we could have blocked it, but it's not.