It seems to me that regardless of how tight we attach keyguards to touch screens, those little fingers seem to find ways to take them off.
I discovered this amazingly strong, thin “Velcro” that is not Velcro at all. I tried to peel off a keyguard on an iPad and could not. Yet the “suction cup tape” is removable and won’t scratch or damage the screen.
Have a look: www.laseredpics.biz/suction-cup-tape/
I hope to get some at the Centre soon. If you know of a Canadian distributor please post it in the comments.