Focos - Your Portrait Mode photos become amazing masterpieces of art
Slide Camera - A 3D Camera for the iPhone
Fuzion - Create stunning portraits and visuals from your iPhone
Lightsynth - The first camera which supports mobile ADR - Adaptive Dynamic Range, Lightsynth lets you have done with all kinds of exposure trouble under various tricky lighting situations such as daylight skies, backlit, or low-light.
Portrait Mode + - Change focus, swap background (and more) of portrait photos
VSCO Cam - VSCO Cam is an iPhone, iPod Touch, & Android camera app w/ elegant, minimal processing options.