How does it work? Each activity that humans partake in has a certain level of watts. This wattage is based off of the intensity of the activity, your weight, and the activity type. Humans burn calories when performing a certain activity at a certain wattage for any length of time. This calculator has preprogrammed information about various activities and uses your weight and duration of activity to determine the amount of calories that you burned during that period of constant movement. Again, this calculator gives estimates, so actual calories burned may be +/- 200 kcal.
This app can be found FREE on the Android Market (now called Google Play) at:
Calories Burned Calculator
I believe that it is also available at the iTunes App Store