Nike+ Running is a brilliant running app that automatically tracks your run; your pace, location, overall work-out... It automatically pauzes your work-out when you're not moving and resuming it when you're on the go.
After each run you can add your mood, type of road you ran on and custom notes to keep track of your runs.
Each run you can share with custom pics on your social media afterwards.
Nike+ Running gives a good overview of your latest run. If you want to challenge yourself, you can join a challenge like run half a marathon and get a trainings plan according to your needs.
If you prefer challenges with friends, you can set a challenge and invite friends to join it.