Endomondo is great. We found the app to be intuitive and extremely easy to use. Though it lacked laser like accuracy, the measurement errors were consistent with problems in consumer GPS technology. These errors, ranging from none at all to upwards of 10%, were nothing that most people would mind and the benefits of tracking runs in this way far outweigh the minor shortening or lengthening of runs encountered on this app. The community website (http://www.endomondo.com) is useful and provides plenty of tools for users to stay on track for their training goals. I recommend Endomondo for all workout situations we tested.
Here is a brief breakdown of all the different tests I performed and the results:
The track tests were designed to see if Endomondo would be able to perform with a high degree of accuracy on two different types of running workouts. On the pace run, Endomondo recorded my distance, .5 miles, exactly – despite making errors with the start and end spot. Endmomondo did not do as well on an interval run where a 20 second sprint was followed by a 10 second cool down period. The distance was off by approximately 5.7% and the app did not do a great job of recording changes in my pace, essentially measuring my pace a flat line.
Most people run outdoors in some sort of suburban context. Following streets and using Google Maps (or driving) to measure distance traveled is a very common way for many people to get some sort of bearing on how far they travel when exercising. We put Endomondo to the test against this method and found that the app did a great job of measuring runs in suburbia, giving results that were often only a small bit off of what Google Maps would measure. In a there-and-back style run Endomondo and Google differed by as little as .01 mile and since Google does not give a hundreth of a mile this should be seen as no difference between the two. In a longer loop run the difference between the two jumped to .1 mile, but due to the nature of the track it appeared as though Google measured the run long, preferring to measure along the middle of the street rather than near the sidewalk where we ran.
With the increased interference between the Galaxy Nexus I used for the tests and the GPS satellites in the sky above I found that Endomondo suffered in nature runs where woods made up a majority of the distance traveled. Though I was unable to compare exact distances between Endomondo and third-party measurements I was able to visually compare routes against maps and against Endomondo itself. As a result of these findings I determined that Endomondo worked well enough for nature runs, but third party measurements should probably be used whenever possible since I suspect this data to be in error of at least 10% of the distance traveled, with the error potentially being more.
Endomondo should not be expected to measure the distance traveled in a workout indoors. The interference introduced by the ceiling of a building is just too great. In buildings with windows in the ceiling I found that the app worked much better, but even under these conditions I consider the app a failure. Endomondo does let you edit distances traveled on the website, making it useful still to track your time and heart rate (if you have one and can sync it to your phone using Endomondo). No GPS is going to work well indoors to track your distance traveled so this should not count against Endomondo. I would still use the app indoors and just edit the distance traveled in order to keep track of my workouts for all seasons of the year.