I saw this app on a friend's tablet. It was running Android but i've also seen this same exact functionality on an iPad a few months ago. But i don't know the name of the app. Here is how it works: You switch on the iPad and the first thing it shows you is a screen with a square of 9 dots. You have to move your finger in a specific pattern in order to unlock and use the iPad. If you try more than twice and fail to get the code right, the iPad shuts down. I thought this was really neat and protects my device against unauthorized access, but i have no idea what app is that? Hopefully it's free.