Most of Munchable is a barcode scan: point the phone at a pack, get an answer about whether it suits your gut. Sometimes the barcode is one we do not have yet, and then the app asks you to photograph the ingredients panel instead. That screen is 1,256 lines, and almost all of the interesting decisions in it are about one question: will the small print come out sharp enough to read?

The camera is a card on an ordinary page

* THE SCREEN IS AN ORDINARY MUNCHABLE PAGE. Heading, explanation and buttons * are on the cream page in the app's own type, like every other screen, and * the camera is a card in the middle of it. Nothing is drawn over the picture * on a dark band.…