Use this application to fine tune your voices before any vocal performance. It is easy to use!
Just pick the chord you want to hear and here it is, you are ready to sing!

Concerts³ tells you which artists of your music collection will be performing within a certain range of your location.

Pretty handy.

RockOn is a music player for Android. It has a nice all-graphic UI interface, location-aware concert info and automatic album art. It is the player of choice if you prefer browsing your music library by album art.