This work focuses on Fitbit as an activity-tracking device that uses a three-dimensional accelerometer to
sense user movement. The device collects information about steps taken, and by combining that with user
data, it calculates basic measures such as distance walked, calories burned, floors climbed, and duration and
intensity of activity. Fitbit automatically syncs users’ data to desktop and mobile applications, providing a
variety of numerical information representations
Fitbit Flex is a wearable model and is worn like a watch on the wrist (Figure 1, left). It has a simple display
of 5 LED lights that represent the number of steps taken in a day, and it vibrates to indicate that the
personal goal has been reached. So, for example, if the activity level is low, only 1 or 2 LED lights will be
lit. Fitbit One is clipped to one’s clothing or can be put in a pocket (Figure 1, right). This is different from
Fitbit Flex, which offers a digital display that shows the number of steps and other types of information.