My current obsession is with photo apps on my iPhone. I got the Quad Camera app a couple weeks ago and really love it. Then I purchased the Color Splash app and pissed my pants due to its awesomeness. Then I downloaded the ezimba app for free this morning. It's almost more than my Flickr can handle!
The Color Splash app is genius! It takes all the color out of a picture, then you can paint the color back into it wherever you want. Totally worth the $1.99!
Then I discovered this! The quad animator lets you make .gif files out of your quad shots. How cool is that!?