iOS: There's no shortage of fitness-tracking apps in the iTunes App Store. However, if you want to combine all your other apps into one, Argus is an app that lets you see all your health data in one place.
By itself, Argus tracks your walking and basic nutrition. What makes Argus interesting is that it integrates with a bunch of other fitness apps, including MapMyFitness, Instant Heart Rate, Sleep Time and plenty more to give you an overview of all your health data in one place. All of this data is then combined together to show you the bigger picture of your health. Azumio doesn't do whole heck of a lot by itself, but if you're already using a bunch of other apps to track your health and want too see all that data in one place, Argus is a good place to do it.
Argus by Azumio (free) [iTunes App Store]