Poladroids are really cute and are now supported outside of just the mac native platform. Plus they always have that great muted color.Photoshop lite made the list but many said it bogged down their Iphone.
The mill from the UK is really cool and allows for a lot of individual color tweeks. Thanks to Mike Sugrue for that one.
Camera bag is one of the most useful for catchy fun pics of about anything. It is very user friendly.
My Personal favorite is the best camera You can frame,vignette, and send everything to all the popular social networking sites out there. It is also great for quickly converting to Black and White It's easy to use and you have probably already seen its effects all over!