DemoApp is that mystery application that coexists in the iPhone's Applications folder along with all the standard apps like Google Maps, Calculator, Stocks, and so forth. We've known for a while that it had something to do with movies but until today, we weren't sure what it did. Today, I can confirm that it does what most people have suspected: it plays a single movie over and over in a repeat loop. It does not, as others hoped, allow you to play video out through your dock. Here's the down and dirty on DemoApp.

Where is DemoApp located? It's found in /Applications. You will not be able to see this application without hacking your iPhone.