my wife just showed me the Sherwin Williams paint app. using the built in camera, take a pic of an object and drag 'n drop the color into the color palette and it'll recommend colors. great tool not only for selecting matching or complimentary paint colors, but also very handy tool on how to color coordinate your outfits. for a color-blind guy like me who has trouble getting dressed in the morning it's fantastic.
my fave is the Camera Bag app for $3.99. take pictures and manipulate them from a 7 types of camera styles, like Helga, Mono, Fisheye, Cinema, etc. Helga is awesome!