*** This is the free version of Snap Filters. It includes all features from the full version with no limitations, but adds a watermark at the bottom of your images. ***

Built with speed and ease of use in mind, Snap Filters lets you apply simple filters to your photos (taken from within the application or loaded from your library) and make the most out of your iPhone's camera.

It only takes a few seconds to review three styles of coloring filters (from desatured to intense) with a choice of nine tints for each (the center image is always the one that isn't colorized), or two types of black-and-white processing (regular or with added contrast), simulating taking a picture with a color filter on your lens (the difference won't always be spectacular, but you can choose the variation that makes details pop). One more button and you can choose from different styles and intensities of vignetting, and toggle whether to crop the photo to a square.

Snap Filters remembers your settings from one photo to another, so if you find a style you like, you'll never have to change the settings again. But if you're the obsessive type, you can have fun quickly going through each of the filters to find the perfect setting for each of your pictures.

Once you've saved your image, additional buttons will appear to let you either copy it to the clipboard, or e-mail it directly from within the application. You can even set up a default e-mail recipient, subject, or body in the Settings application (so you can very easily send your photos to Flickr by setting up your upload e-mail address, and adding the tags "iphone" and "snapfilters" to the message body).

You can find example images here:
http://www.flickr.com/groups/snapfilters/
Don't hesitate to add your own photos to the group!