Most often, people use Fitness trackers for keeping track of their fitness activity, set achievable goals and to motivate themselves. Fitness trackers are mostly wearable electronics that measure/track your activity such as steps taken, distance walked, calorie consumption and even heart rate in some cases. Most fitness trackers have an accelerometer that helps in tracking our activity. Some fitness trackers may also have altimeter, music player and many other features. So, how does the fitness tracker do it?