The hardest thing about being on a diet (we're told) is sticking to it, but there's no arguing with the effectiveness of LiveStrong.com's Calorie Tracker app for BlackBerry.
Calorie Tracker is a simple idea - tell it what you ate and what exercise you've done today, and it will tell you what your daily target number of calories is, and how close you are to it.
It work, too. Nothing matches the shame of typing in 'Big Mac' and guiltily clicking 'I Ate This'. There are 525,000 food and restaurant items to search for, and despite LiveStrong's American roots, users this side of the Atlantic shouldn't have too much trouble - haggis and Marmite both have entries, for instance.
It isn't just food, either. You can search for various exercise routines - so you can tell the application how far you've just run or how much you've lifted, for instance, and you can enter your weight to track it as well. You can access the data via your phone or at www.livestrong.com.
NEXT: our expert verdict >>