Maybe I'm overestimating the learning capacity of two-year-olds, but isn't that something you'd learn after a few times?
(and the big grey button on the ups in daddy's office is fun too. makes beeping noises.)
There should be a way to enable kid mode, and use the switch to disable the home button for a while. At least till he figured that out.
1: Open app. 2: Watch app for 3 seconds. 3: Close app. 4: Goto 1