This app was originally posted on the front page in December 2010, and I couldn't find a thread on it. It's FREE.
This is an app that just has the basics-locating the spot to do hands-only CPR, and a video on doing it and the rhythm. It's nice to have on the touchpad or phone in case something comes up. Also, If you have it on your device, you're probably going to re-watch it when you rediscover it every few months-and that isn't a bad thing.
The songs that have the same beats as the compressions are The Bee Gee's 'Staying alive', and Queen's "Another One Bites the Dust."

The app itself isn't fantastic. Of the two videos, one hasn't been scaled to the touchpad. But the app seems to cover the basic information you need.