Weight alone doesn't tell the whole story - pro athletes often have BMI's of 30+ making them technically obese, but they run 100 yards in 10 seconds. Muscle tracker records your measurements for all your major muscle areas, so you can see how the shape of your body is changing.

However that's when things get interesting... by combining all of your data we can calculate your muscle density. Regardless of wether your weight and measurements are increasing or decreasing, if your density is increasing then that's good evidence that you're improving your body tone: swapping fat for muscle.

The App supports Kg, cm, pounds, stones and inches (selectable in the Settings App, along with Gender). You can also use iCloud to sync your measurements between your phone and your iPad. If the prospect of updating 13 measurements of your body on a regular basis seems daunting, check out our Tum Tracker app, which provides the same functionality [subject to version release dates], using a slightly less accurate 7 measurements.

Settings are in the standard Settings App. There seems to be a struggle to find this, but its the same place that your settings are for every other app. It's the Apple App you use to configure your phone - it looks like a set of Cogs.