When you go to print something on your iPhone and you are presented with the thumbnail of the first page (the iOS equivalent of the print dialog), two-finger pi

When you go to print something on your iPhone and you are presented with the thumbnail of the first page (the iOS equivalent of the print dialog), two-finger pinch to zoom in on that thumbnail. You will be presented with a PDF of the output, with a share button in the corner to shoot the PDF wherever you'd like. Most useful ultra-hidden feature ever.