PowerSketch is described by the developers as ‘a fascinating yet easy-to-use app that brings out the Picasso in you. 10+ realistic and creative sketch effects come standard with PowerSketch, including rice paper, picture-in-picture, shadow, wash, neon, and more. You can capture an image and turn it into a sketch or select an image from your camera roll or gallery to convert to a sketch’. This app usually retails for $0.99/£0.69 but today you can download it for free. Click here to download.