Ive been using SmartRunner for about a year; first on my Palm Pre and now on my iPhone 4S. It was a bit unreliable for me on webOS, but has been solid on the iPhone. The app gets a GPS location quickly, and remains connected for the entire route, whether Im riding the bicycle or walking.
The ability to customize the voice notifications is very useful for me, as is uploading completed routes to the SmartRunner website.
I have tried other apps that claim to have similar functionality, but none can compare to SmartRunner, in my opinion.
gc916 about SmartRunner Pro your GPS coach for jogging, cycling and marathon