SARAS uses Google Play Services library to take GPS fixes as default. However, some devices do not support this library. In such a case, SARAS uses Android Location Library. First of all, these two GPS methods are tested in terms of resource consumptions, as in Figure 1(b). As shown in Figure 1(b), using Google Play Service library consumes less CPU and power consumption. LCD power consumption values depend on the number of merchants displayed on the screen. These values are close to each other. The only exception is the battery life.