To measure the distance this time, in the application is only have 2 unit are miles and kilometers, no units smaller than this. The measurement precision error. The Internet is another cause unstable one. When looking at the picture of the GPS used to measure distances, some of the photos is that run from the beginning and end pass from beginning. Some of the photos is from beginning but end not reach. In fact, when we start the measure the point where ends at that point, which shows the fact that with the images we see that do not match the results come out no more accurate