Like shoving a personal trainer in your shorts.

Update: 3ish years later, and this is still 5 stars and still the only running app I use.

Best running app on the iPhone hands down - cadence coaching, user laps (!!), shoe mileage, Pebble integration (with a full-on custom Pebble app, so you can trigger laps, pause, and show multiple pages of the huge amount of info iSR knows!), weather/fastest song/more recorded each workout, ghost runs, extreme interval editing, great graphing and calendar view, smart switching betw gps and accelerometer when gps coverage drops, uploading to RunKeeper, MapMy, email, and even up/download backups via Dropbox...

Awesome sauce.

Bottom line: best running app on the iPhone. Period.

tim05401 about iSmoothRun, v5.4.1