Gorilla Cam comes from the same people who created the famous Gorillapod twisty camera tripod mount, which can be wrapped around branches, table legs and the like. The idea behind the app is that it can act as a complete replacement for the iPhone's built-in camera software, while offering several extra features.
For example, there's a spirit level to help you keeping your shots straight and a grid overlay to allow you to apply the rule of thirds to your pictures. It also includes a three-shot burst mode that fires off three quick snaps in quick succession, as well as an anti-shake feature to help you avoid taking blurry shots. There's even a simple time lapse option, should you fancy trying your hand at simple time-based effects.
For a free app, Gorilla Cam is surprisingly well designed and offers a bumper range of useful features.