Hello illuminaries, I recently set up a user account for my three-year-old on our iMac. She's great with it, but she has a tendency to open multiple apps at a time, each with their own annoying kid music, and you can imagine the ear-bleeding cacophony of all of them playing at the same time. Is there any way in OS X or a third party app to disable multitasking? As in, nothing backgrounded but apps are 'force quit' before another app can be opened? It's a kid account with full parental controls so I assume our important stuff should be shielded from any tweaks. Thanks!