So I've gone how far?

All week I've been using apps on my phone (an android) to track what I've been doing.

I've slowly realized that the two I've been comparing regularly tell me I've jogged for roughly the same time, but quite differing distances. Why does one say I've gone 1.54, and the other 1.79 miles? And which is right? It affects not only how far I can claim but also the speed of course. The maps seem similar - it's just the distance they register for the same run that varies. Hmmmm.

I know it's silly to use two; and of course I'd prefer the one that says i'm slightly less of a slowcoach going nowhere.... But i'm sure there must be a right answer too, and just choosing based on the one that makes me feel better seems a weak criterion. Any advice wonderful army of Janathoners?

Still, I am proud to have completed day 7 (even if there does seem to be still a LOT of this Janathon month left) and I can surely claim 1.5 miles at least? I think so anyway!