i have a galaxy tabs 10.1 which i gave to my brother. the problem is he keep installing app whether its a playstore apps or from unknown source apps. this makes the tab very slow. im too lazy too find out what makes the tab slow. so usually i just reformat the tab. and then he keep installing stuff again. and the process repeated again and again. is it possible for me to just install a few common stuff like facebook app, whatsapp etc and some few games and then restrict the device from installing any kind of app whether it is from playstore or unknown source. he knows how to turn on the "install from unknown source" things. so by just turning the feature off will not stop him. please kindly help me. thanks