Five low- or no-cost iPhone image editors

Because it takes such amazing pictures, the has become the pocket camera of choice for many users--myself included. The phone's built-in camera is easy to use and always handy. What's more, the App Store is loaded with a number of great third-party apps to help you make the most of your photos. And many of these filters will cost you very little--or nothing at all.

Apps like , , and deservedly grab a lot of attention. But I'm always on the lookout for image-editing apps that fly under the radar. Here are five I've used lately to tweak my mobile photos.

from actually does what other apps might try to fix--it adds pixelation to your photos. Ever wanted to make yourself into an avatar for an Atari 2600? With dozens of possible adjustments, the $1 Pixel It can make a creative mosaic or make your image look like it was taken with an old . (Remember those?)

The free from provides a perfect example of a single-function app that does its job well. Take or load a photo, make some simple adjustments to brightness, contrast, tone and color, then get to some crumpling. The old paper texture and edges options make your picture look like it has been folded up and kept in grandpa's wallet for a few years. It's a cool effect--one I haven't seen in other apps.

If you'd like to jettison Old Photo Pro's ads, the app offers a $2 in-app purchase that does precisely that. More important, the in-app purchase also adds support for higher-resolution images.

is, as its name would suggest, free. This is an fun double exposure app that allows you to overlay two images into one. The controls are a bit quirky, and DXP Free doesn't provide a lot of options for adjustment, so it's best to plan ahead. Figure out what images you want exposed together, choose your composite effect, and then go for it. The final images are often surprising, but I found the best results when I kept it simple. A is also available for $2.