Mobile devices, such as phones and tablets, are becoming increasingly popular. Research shows that approximately a third of the world׳s population owns a handheld device [3] and [4]. Moreover, these devices are constantly improving regarding processing power and memory space available [5], which makes them powerful enough to perform complex tasks, such as tracking. This scenario favors the creation of numerous types of applications since such devices create several opportunities that are only possible when the user can be mobile.