I use endomondo & strava apps on my iphone. I like to record my mileage to see how far I rode in a year. These apps make it super simple as I don't have to write anything down, just press start & end. They both have gps data on them & it's a nice freebie since I', tracking anyways. I suppose it would be of more use if I was on a tour or something, but it's still nice to have. I don't normally look at the apps while IP'm riding though. I just use them to track & store the data.