The iPhone 5 brought with it extra screen real estate, and Apple left it up to developers to optimize their apps to take advantage of the added space. Although many apps have been designed with the larger iPhone 5 display in mind, there are still some that have fallen through the cracks. Now with a jailbroken iPhone 5 and the FullForce for Phone tweak, you can stretch or expand these apps.
This means no more letterbox bars on the top and bottom of your iPhone 5 screen. FullForce knows which apps are not optimized to fill the screen, and will ask you what action to take the first time you run an app. Settings -> FullForce includes a list of apps and the behavior you want to take place when filling the iPhone 5 display.
Apps can be stretched to fill the screen (like with a full-screen game) or expanded, which moves menus to the top and bottom of the screen and extends scrolling content areas, for example. The FullForce tweak was first implemented on the iPad by developer Ryan Petrich to extend iPhone apps on the tablet display. Now he brings the capabilities of FullForce to the iPhone 5.
To make the most of your iPhone 5 display, jailbreak your iOS device with evasi0n then get FullForce for Phone from the BigBoss repo on Cydia for $0.99