Why won't any of the apps on my iPhone work?

[Mickey]

Try fully turning off your iPhone. To do this, hold down the lock and home button until a slide bar appears (slide bar as in, the thing you have to slide to unlock your phone). It should say something like "slide to power off." Slide that bar and your phone will go completely black, and wait ten seconds after that happens. Once that time is up, hold down the lock button until the Apple logo appears. From then on, wait, and the phone should be back on within a minute.

Sometimes the iDevices just freak out a bit and you have to turn them off like that.. It's weird, but at least it's that simple to fix.

Hope I helped!