In the spirit of My Dream App, I've invented my own dream app. BestAppEvar.app would be able to divine what needs to be done by detecting my brainwaves, and would then do it when I hit the button. To make it easy for you to implement, I've already designed the UI:
So, why hasn't it been made yet? Come on, you lazy coders! The hardest bit would be the brain-computer interface, but there are example I/O Kit projects on the ADC site.