Doc Scanner

Photograph a receipt, a form or a contract and it comes back as a proper document: the page straightened out of its perspective, the lighting evened up, and as many pages as you like saved into one PDF.

Drag the four corners onto the corners of the page. The photo is then flattened, which is what turns a picture taken at an angle into something that reads like a scan rather than a snapshot of a desk.

Three looks: the original colour, a cleaned-up greyscale, and black and white for text. Black and white judges every pixel against the area around it rather than against one level for the whole page, so a photo with one half in shadow still comes out readable instead of half black.

The camera, the flattening and the PDF all happen on your device. No page is uploaded, nothing is queued on a server, and the app keeps working with no connection. Pages you have taken are kept on the device until you save the PDF, so a reload or a phone call does not lose the document you were part way through.

Install it to your home screen and it opens straight to the camera, which is the point: the scanner you want is the one already in your pocket.