Snapseed, $5, www.niksoftware.com

The iPad may have a so-so camera, but it has some first-class photo-editing software.

Nik Software, known mostly for its Photoshop plug-ins, has an iPad app that brings some powerful photo manipulation to the tablet for a reasonable $5.

Called Snapseed, the app has the expected features, like auto-correct, cropping, contrast, brightness and saturation adjustments. It also has a very handy white-balance adjustment for taking the unwanted tint out of a photo.

The fanciest feature is selective adjust, which lets you apply effects and filters to a section of a photo. It's a great way to fix an overexposed background or to even out spotty lighting.

It's fairly easy to use, too: You choose a filter by running a finger up or down the screen, then choose how much to apply by moving your finger left or right.

Instructions pop up on an overlay when you open features the first time. From the help menu you can make those directions visible again or see video tutorials.

Besides the photo touch-up tools, there are creative filters that let you change photos to black and white or add tint, textures, vignettes or borders.

Finished photos can be printed or shared by e-mail, or on Flickr and Facebook right from the app.


Third Rail System, $90, www.thirdrailmobility.com

The Third Rail System may be the lightest iPhone case with an auxiliary battery, or it may be the heaviest.

The system consists of two parts, a case without a battery and a backup battery that snaps onto the case. With the battery in place, it is still pretty sleek and lightweight.

But you can piggyback more batteries on top of the first battery, building a bricklike case with a monthlong charge.

Obviously, the battery-brick scheme isn't very practical, but the ability to switch out a full battery for one that is running low may be.

The system offers another trick. The batteries have a circuit that allows them to completely transfer their power to a different battery. When the battery is attached to the case, it will top off an iPhone. Then, the battery can be removed until it's needed again, giving you less to carry.

Ingenuity doesn't come cheaply, though. The Third Rail system is $40 for the case and $60 for a battery and charging cable, or $90 for the pair.