Free at the mo. Can't whinge for nowt.
iTunes link: http://itunes.apple.com/us/app/front...ign-mpt=uo%3D4

Seems to do a decent enough job.

Sometimes, it’s just not possible to get the dead-on square, front and center shot you want. The building is too tall or there are too many people directly in front of that painting on the wall. FrontView is a simple, great utility for fixing any undesired perspective in your images like off-center snapshots of paintings, billboards, architecture, posters, etc. making them appear as if taken from the exact front and center.



FrontView is very easy to use. There are four corner spots that you move to the corners of the object. There’s an excellent preview-in-preview window that helps precisely place the anchors. A white frame shows where the image will crop. You can also use the frame to align the edges to buildings or other objects with more complex perspective. Hit next. FrontView also has a dial to adjust your aspect ratio, if needed (a great addition to tweak the crop). Save. It’s that easy.
FrontView doesn’t save in full resolution — there is some pixel loss, but depending on how tight the crop of the source image is, it usually saves in a very usable high resolution and even possible to get very close to the original 5 MP resolution on an iPhone 4.
FrontView seems to be a little laggy for me. It’s quick, but didn’t feel super-responsive on my iPhone 4. It doesn’t support iOS 4 backgrounding, so if you exit the app for any reason — say, a phone call — you’ll lose whatever work you’ve done. It also doesn’t support a fixed perspective fix like the excellent dotfunc(camera) does. All four points are independent.
These are all minor quibbles and certainly aren’t dealbreakers for me. The app processes so fast and is so easy to use, any work lost can quickly be redone and the precision of the preview screens help overcome the lag of the app.
A perspective fix utility is a good one to have in your toolbox to help tweak the image when you can’t get the straight, center shot you want. FrontView is fast, easy to use, and saves at the highest possible resolution. For a buck, it’s a great addition to an iPhoneographer’s toolbox.