I'm wondering if anyone is familiar with this iPhone app.

I do not use an iPhone but will consider one if this software is as good as it seems. It would be fantastic to have something that can randomly select music from my library by the tempo of my workout.

According to the site, http://www.bowleggedturtle.com:

"FitBeat is a unique iOS app for runners and other fitness enthusiasts. It senses the tempo of your workout then automatically fits songs from your music library to that rhythm, so you are always exercising to the beat! It also accurately tracks and graphs your stats and lets you share them with friends. "