Adidas and Spotify are already quite friendly, especially when it comes to supplying workouts with the proper tunes. The duo teamed up for offline playback on the Adidas SmartRun watch and soundtracking a jog with the help of RunKeeper. Now, there's an Adidas Go app that varies music based on movement tracked by your iPhone's accelerometer. Using that piece of smartphone tech, the app measures stride rate and matches songs from Spotify's library -- based on your listening habits -- to help you keep pace. When the run is over, stats like time, distance and pace can all be reviewed, saved and used to calculate your Adidas MiCoach RunScore. And if you'd like, you can save the collection of tracks the music service piped in along the way, too. Ready to lace up those sneakers? Well, you'll need an iPhone 4S or later to take advantage of the free app that's available at iTunes now.