When I was thinking of a new photo app to review, I was going to do CameraBag which seems to be a pretty popular app. It's consistently in the top ten in paid iPhone apps. But as I was looking at my photo apps, I clicked on CinemaFX (which I have to admit is an app I rarely used) and realized that it is a pretty great app. It's actually better than CameraBag because not only does it give you the different style options, it actually lets you adjust the settings to your specifications.
With CameraBag, once you choose your style that's it. If the original photo wasn't perfectly exposed, maybe the style you choose will be too dark or too light and it just doesn't look the way you want it to. With CinemaFX you can use the sliders to adject the style to the way you like it.
Another cool thing is that you can layer styles. You can layer styles in other apps as well but normally you have to save the edited photo, then go back to your photo library and select the edited photo, add a new style, rinse and repeat. In CinemaFX you can add a style, click the "CinemaFX" logo up top, press done, and keep adding styles.
This the Charmed Glow style.
This is Egyptian Glow on top of Charmed Glow.
This is Surveillance Cam on top of Egyptian Glow on top of Charmed Glow.
If you just want to edit the brightness and contrast to the original photo, you have that option as well.
There are also options for image size (larger photo resolution for 3GS).
For only 99 cents, this is a pretty great photo app to get. Compared to CameraBag's $1.99, I think this app gives you a ton more options and needs a lot more recognition*.
*as on 3/29/10 it's number 71 out of the top 100 iPhone photography apps compared to CameraBag being at number 9.