This app checks out your photographs and gives you helpful information.

Details include: Picture format, Exposure, Clipping, Overall Exposure, Rule of 3rds Sharpness, Dynamic Range, Red, Green, and Blue exposure with clipping, 4x6 printing size, Compression level (high is bad), Color and averages, and People (face detection).

It also rates your photos based on what it considers good from those given properties it checks, though that's just a fun way to test your skills and try to take a photo with a 100% score (good luck, I never have!). It's a fun and helpful app that is good for novices and skilled photographers alike.