Really enjoyed my run today, but after checking it on my app, I got annoyed by running apps in general.  Right now I'm following a plan to generally increase my weekly mileage.  Yesterday and today I had workouts planned for 38 mins at an easy pace.  I started each workout in the same place right outside my house.  Both days I stopped the workout within a few seconds of the app telling me the workout ended.  So far so good.  Today, I was following the exact same route as yesterday, and I hear the 3 minutes left voice prompt.  I was feeling good so I picked up the pace just a little to see if I could get just a bit further than yesterday.  Nothing crazy, just having some fun.  And I did, I got may .1-.2 miles further than yesterday!  Yay!  Right?  Except my app is telling me that today's run was .2 miles SHORTER than yesterday's.  
It's a little thing that is probably just gps error, but it's annoying.  It means the pace data is completely off.  According to the app (MapMyRun, btw) I ran faster yesterday than today, even though I clearly ran further in the same amount of time today.
Bah!
Out of curiosity I exported both workouts to Runkeeper and it seem to recalculate the distance and correctly identifies the second run as longer and faster than the first one.