iOS displays the Status Bar in most applications so the user can see important information such as the battery percentage and current time, however not everyone feels the need to see this information in the middle of using their device. If you have come accustomed to full-screen applications in OS X Mountain Lion or Lion, then a new and free jailbreak tweak dubbed Maximization by iOS developer Rudolf Lichtner may excite you.

Maximization, once installed, forces full-screen application