Before I got my Garmin I was a big fan of the Runtasic app and used the Pro version. I think it's usually £1.99 or £2.99 but today it is free for download in iTunes and google play.
It is a GPs tracker app which works in the background of your phone and maps your run. It's best used after week 7-8 but if your interested for the future it is free today.
Runtastic PRO Running, Jogging and Fitness Tracker by runtastic