Doodle Fill

There is an old topographical chestnut illustrated as a political cartography problem: if you have a map with a given number of countries clustered on it, what is the fewest amount of colours you can use to give each region a different colour without bordering on another region sharing its colour? It's rather more intellectual than this game, but ultimately they share the same concern.

This game presents a number of aesthetically pleasing abstract geometrical line drawings in black and white, divided up into various complete segments. At the player's disposal are four pencil crayons, each of a different colour. The player's challenge in a given level (and there are a lot of them) is to colour in every part of each level's drawing -- tapping on a crayon and then the area flood-fills the area -- without having any two adjacent areas of the same colour. Making things interesting, every level has a time limit -- and your own manual dexterity on the small iPhone screen may vary. Areas coloured in error can be re-coloured as often as you like, but the clock is always ticking.