If you get the same box whichever app that you tap then it sounds like you have VoiceOver (one of the accessibility features) 'on'. Try triple-clicking the home button and see if that turns it off, and if it does you can then change what a triple-click does via Settings > General > Accessibility > Triple-Click Home.
If that doesn't turn it off then you can either turn it off directly on the iPad (you need to use a tap-to-select and then double-tap to activate/type process and 3 fingered scrolling e.g. to open the Settings tap it so that it gets the box around it, and then double-tap it to open it) to go into Settings > General > Accessibility and turn VoiceOver 'off', or you can do it by connecting to your computer's iTunes : http://support.apple.com/kb/HT4064