Nik Software offers some truly remarkable photo post-processing software for the Mac, but it's not cheap, ranging in price from $100 to $200. So I'll admit, when I first downloaded Snapseed -- Nik's $4.99 universal iOS app -- I wasn't expecting a lot. I just didn't figure Nik would cram that much into such an inexpensive package. I was very wrong.

Like iPhoto on the Mac, Snapseed provides you with simple tools to help adjust basic problems with your photos, including color, exposure, straightening, cropping, and "tuning," which is a broad category of corrections like manipulating saturation, white balance, and contrast. Built-in tutorials, tips, and video lessons help you get started.

Snapseed's universal nature makes it work on the iPhone, and that's useful for making minor adjustments to images. It's a very different story on the iPad, thanks to the tablet's increased screen real estate: Snapseed turns the iPad into a high-powered photo editing and post-processing workstation.

Nik Software brought the "U Point" technology from its Viveza software to Snapseed's Selective Adjust feature. U Point lets you place control points on the image by simply pointing to parts of it; you can adjust the radius of these control points, essentially creating a mask. Swiping horizontally near these control points enables you to select contrast, brightness, or saturation, and swiping vertically lets you adjust the values of those enhancements. This lets you darken a background while emphasizing the lighting of your subject, for example.

Snapseed has a number of filters you can use to further enhance your image: Black and White; Vintage, which adds an color cast to simulate photos shot on vintage or expired film; Grunge, which adds a damaged cast to the image; Center Focus, which lets you blur the background; and Frames, which let you add a variety of frames to the edge of your photos.

Some of the effects are gimmicky -- you'll run out of things to do with Grunge pretty quickly, but the Black and White filter is classic and adjustable; even Drama can help you achieve almost HDR-like effects by exaggerating contrast.

Each filter has a number of primary styles or textures that can be applied to further customize the look and feel of your photos. The net result is hundreds of possible combinations of filters and effects that can be thoroughly tweaked until you get just the effect you're looking for. There's no zooming, unfortunately, so you can get quite the precise control over your changes that you can, for example, by using Nik's software for Apple's Aperture or Adobe Lightroom.

Once you're done tweaking your images, Snapseed has built-in email, Facebook, and Flickr sharing tools, and if you have an AirPrint-compatible printer, you can print straight from the app, too.

If you're dumping RAW images straight from a camera through Apple's Camera Connection Kit, you're going to need an iPad 2 or an iPhone 4; Nik says Snapseed will work with up to 16-megapixel images on those devices. If you're relegated to an original iPad, iPhone 3GS, or iPod touch (third or fourth generation), you'll need to limit yourself to 6.25 megapixels or lower -- also, RAW image processing doesn't work on those devices.

The bottom line. Whether you're an amateur or pro photographer, Snapseed can help your photos look better. At $4.99, it's a bargain, especially when you consider what Nik Software's own post-processing software costs for the Mac.