3 of 7Image
You can press almost anything to take a picture with Vignette but it's buggy and features are subpar. The demo is free and the upgrade version is $3.99.
LittlePhoto is free and possesses outstanding editing tools but the shutter is slow.
CameraZoom is a well-rounded app with a full-range of precamera settings but it suffers from a slow shutter. $2.99.