Sometimes you just need your weight in black and white, and here's where Weightbot comes in. It lets you record your weight every day (if you like) and plot your progress on a crystal clear graph, so you can see exactly how you're doing.
We also really like the fact that it calculates your all-important body mass index for you too - something many of the others don't. If you're serious about losing weight and want to keep a proper eye on your progress, this is worth £1.49 for the brilliant fuss-free interface.