Bejeweled 2 is one of those vital applications that all game systems worth their silicon should have, in some form or another. Indeed, it's so necessary it's a wonder most systems don't bundle it as part of the firmware – particularly a fledgling format like the iPhone. Not only does it Bejeweled 2 have the stuff from which gaming addictions are born, but it makes good on the promise of intuitive touch controls.

For anyone who's been living on Mars for the last ten years, with their eyes closed and fingers in their ears, let's take a quick look at the skilfully simplistic gameplay of Bejeweled 2. A grid of 8x8 squares is populated by various shaped and coloured jewels. Each jewel can swap places with any other gem immediately above, below or to either side. When a row of three identical jewels is aligned, they disappear and the crystals above cascade down to fill the gap.

Aligning four gems creates a Power Gem, which explodes when eliminated and takes the surrounding jewels with it. The maximum number of jewels that can be aligned in one move is five, which results in a Hyper Cube: a powerful little fella that removes all the gems identical to the one you exchange it with.

Those already familiar with Bejeweled 2 will be pleased to know the game's refined formula hasn't been tampered with, simply optimised for finger control and given a bit of spit and polish to make the gems really glisten on the iPhone's beautiful screen.

The two standard modes of play are included in the iPhone interpretation: Classic and Action. Classic keeps ticking along at your own pace until you reach a catastrophic point where there are no more moves, while Action pits you against a timer and refills the screen should there be no more combos available.

The real difference in this interpretation is, of course, the finger controls. Bejeweled 2 works best on a touchscreen, as the typical stylus controls make it easy to snatch at gems scattered all around the board, particularly in the up tempo Action mode. Finger control is just as simple, though the relatively small size of the crystals could prove frustrating for the sausage fingered pocket gamer. It does support landscape orientation, fortunately, which helps to get your mitts out of the way when holding the handset, and frees up much of the screen for the moderately critical controls.

Although this latest incarnation of Bejeweled 2 doesn't bring anything new to the beloved series, there's no denying it's as essential as ever. For those moments of boredom on coffee breaks, in a meeting at work or squashed into a crowded train carriage, there will be few better distractions than a game of iPhone Bejeweled 2.