I have recently been using the Dropbox scan documents feature on my iPad. I have found that this feature works well, and results in high quality images. However, I have some suggestions for Dropbox to make this feature even better when cropping an image.
1. When cropping, show the image full size or almost full size. Cropping the small image provided is more difficult.
2. The crosshairs provided for each corner of the scanned document are white, and are sometimes difficult to see against the white background of the document. I suggest that the crosshairs be black.
3. An adjustment is provided for each corner of the document. There should also be a midpoint adjustment for each border, so the entire border can be adjusted without using the corner adjustments.