The scale2print app lets you select a photo from your iPhone or iPad photo album. You can then print your photo on a full sheet of paper in 8x10 or it can even print on 4 separate sheet of papers that you cut and glue together using the crop marks printed by the application for a total size of 16x20!
You can print in portrait or landscape mode.
You can zoom in or out, rotate and position your picture for a perfect picture!
All you need is an AirPrint compatible printer. If you do not have the proper printer, you can also email the photo to your email address with the photo attached as a PDF file for you to print anywhere using your desktop computer.
You can view the video on YouTube of the app running on an iPad: