Fancy yourself as being pretty bright? Reckon you're good with spatial puzzles? Prepare to be demoralised. IQ Challenge:Slider is a Symbian implementation of the classic slider puzzles that the elder among us played as a kid in the 1960s. With complete control over the size of the puzzle and how badly shuffled it is, there's a challenge in here for everyone. Screens and links below.

Here's IQ Challenge in action:

The sliders for complexity (how much the computer randomises the tiles for your starting position) and puzzle size (e.g. 5x5) are well done and obvious. Ads everywhere in the free version, of course, but see below for a 'pro' link.

The game in action, with a fairly simple 4x4 grid (should take you a minute or so to solve) and a glimpse of the hardest grid on offer, the 10x10 - if you solve this then hats off to your mental acuity and your eyesight(!)

A nicely pitched title in every way. There's little glitz or glamour, but absolutely masses of re-playability and heaps of 'IQ Challenge'.

You can download the ad-supported free version of the game here, or buy the ad-less 'Pro' version for £1.50 here.