Great product !!

01 2016 update:
Still using this app, still the best iPhone app for tracking and exporting your activity, with a great audio cue system. Exceptionally well supported.

01 2015 update:
Still the best app of its kind as far as I am concerned. Continuously improved by the developer, who responds very well to issues and questions. Works with an awesome variety of hardware and exports to just about any site you can imagine.

Previous review, 2012
This is the only one Ive seen to use the accelerometer together with GPS - so it gives you cadence, and pace/distance info when the GPS is off (I.e. treadmill). Also makes auto-pause feature very functional. Nice interval features, works with a variety of sensors. Also exports data files for use in programs like Sportracks, and to social networking sites. I really like this app and look forward to what the next update might bring. Well supported by author.

DaFox about iSmoothRun, v5.0.4