Its just ok.

Pros:
- Good running plan.
- Awesome user interface.
- GPS tracking seems spot on.

Cons:
- The run log doesnt have enough functionality or information. For example, the distance only shows you your total distance (including warmup and cool down), whereas I would like to see a Run Distance so we arent tracking that ourselves.
- Not good for running on a treadmill. You cant manually update your log or stats after a run.

All in all, its just an ok app. I might be looking for a new trainer soon.

TejasJon about Half Marathon Trainer: 21K Run