Why is the simple activity of making words from an assortment of random letters so addictive? Whether it's during the word rounds on legendary British quiz show Countdown or in a game of Scrabble, spelling out words somehow manages to be fun. This is what iPhone developer ngmoco has tapped into withWordFu, an incredibly simple word game with a dash of flash.

As far as games on the iPhone go this is one of the simplest. You are given nine letter dice from which you need to spell out as many words as possible. Just touch a die to add that letter to the word you're trying to spell, then shake the iPhone when you're done. By default you're allowed to reuse each of the letters as many times as you like (there's a second mode that limits each to a single use per word) and it's a race against time to score as many points as possible, with more time being added each time you spell a word.

Before each round you can shake the iPhone to give you a new set of dice and flick individual dice in order to change any single unwanted letters. During the frantic word spelling numerous power-ups appear, allowing you to freeze time, change dice, score double points and more, adding to the frenzied action. With loads of achievements to unlock, colour belts to earn (this is WordFu remember) and high scores to beat you'll be playing this simple but addictive game for a long time.

It's simple but does just what you want it to do

There isn't a lot that could have been done with the visuals, but some effort has been made to make the dice move realistically and there's a neat 3D effect when you tilt the iPhone. It'd be wrong to say WorldFu looks exciting, but for a spelling game it's hard to see how it could have been improved. You can even change the sensitivity of the 'shake to confirm word' action, which is really the only part of the game that could have caused problems.

There's really very little to complain about, with WordFu doing exactly what it says on the tin - there's even a two-player versus mode playable over a WiFi connection. We would have liked to have had an anagram mode, but at this price (£1.19) you certainly won't feel short-changed with what is a highly addictive little game.