Colouring is a tap-to-fill colouring book with Koala the painter. Pick one of fifteen big paint blobs, tap a part of the picture and the colour ripples out from your finger, right up to the lines, so every page looks neat. The first pictures, a chick and a fish, have a few big parts, so even a four-year-old finishes them. Later pages grow a little more detailed, with parrots, planets and a candy cottage. Stamp stickers and undo with one tap. When a picture is nearly done, a big green tick appears: tap it, and Koala cheers. Every finished picture wins a new sticker set and turns to a new place: a sunny farm, under the sea, the jungle, space and candy land. Save your picture any time.