The source code for CommandQ and all trademarks are currently for sale if any aspiring Mac developers would like an app to get started with. Contact me for more info.
Have you ever accidentally hit ⌘Q and quit an app when you really meant to press ⌘W to close a window? CommandQ stops apps from quitting unless you hold down ⌘Q for a short delay. This gives you time to catch your mistake and let go before the app quits. Simple. Effective. Awesome.