Shazam is great for working out that song that's playing that you just can't put your finger on. And it's about to get even better on Android thanks to an "Auto" background listening feature.
Once activated, Shazam will compile a list of every song that is played. So if you know you're going somewhere that's guaranteed to have good music, have Shazam open and leave it compile a playlist for you to check out when you're back home.
The app is active in the background, but Shazam describes this mode as "battery friendly."
Auto background listening is now available on Android; the feature has been available to iPhone users for more than two years! Better late than never, as the saying goes.