The iPhone 5's longer screen is great, but not all your apps have been updated yet to support the extra pixels. The result is a boxed app, which isn't really an issue until you invoke the keyboard and it's halfway up the screen. FullForce for the iPhone 5 fixes that.

It forces the apps to fill the screen, just like FullForce for iPad, creating an iPhone 5-optimized look and feel without the developers having to do anything. You have the option to stretch the app or not on launch, just in case it causes problems.

It's just 64p-odd, and available from the BigBoss repository in Cydia. Man, jailbreaking feels so good. [iPhone Developers via Ubergizmo]