I read prior reviews that reported nothing but problems, but decided to give it a try.
It did not work on my iPad 2 with iOS 6.1, but does work on my iPhone 4S with iOS 5.1.1. I have been able to do several two, three and four-part scans that it successfully integrated into single detailed images.
One needs good even lighting on the image source, hold the camera parallel to it and to take all shots from the same relative angle. Positioning each shot intelligently with sufficient overlap I found good results were obtained.
One test was to scan an 18-inch long store receipt that had been folded and crinkled in a pocket. Roughly flattened but with many undulations still present, I scanned it in four photos (three would have worked) and ended up with a sharp single image. In this case, the seams were visible, but didnt affect the readability. In other instances I found the seams invisible, much depended on the lighting and angle of the group of shots.
If you need to stitch together high quality landscape photos, use an App designed for that purpose, but this works for my infrequent utility needs. Long receipts, occasional map images, parts diagrams, any instances where capturing a good functional view of a large image is more important than a pristine and seamless copy.
I will be using this App frequently.
Angloplayer about 4xScanner - Smart Stitch!