I've had a few people ask me what my favorite app to use when I run is. I honestly think MapMyRun is the most accurate (in mileage and speed) but my favorite app is Endomondo. I started using Endo when I began running in June and love that it keeps track of my mileage. I love looking back at my history and comparing my splits from my early runs to now.
My favorite feature of it is that people can peptalk you while you're running. So during both of my races (and my long runs) my husband would type text and then it relays the message back to you. It's super encouraging (especially on long runs when you're by yourself) to hear a voice that's pumping you up.
Another great feature is that it has live tracking that your spouse (or whoever) can see where you are on the computer. I use this as a safety feature in case (God forbid) something happened to me. Overall, I think it's a great app :)
Other apps that I tried were complicated and way too many stats for me to worry about.
Hope this provides the answer that everyone was looking for!