Created by PopSci's sister mag Sound + Vision, BackStage is an app that does much more than inform you of concerts. BackStage serves three main functions: The first is a concert calendar that informs you of concerts in your area based on data from your iTunes library and your current location. The second is a comprehensive music search engine that allows you to search for and view videos, listen to albums, read artist biographies and even purchase tickets. Finally, BackStage allows the user to share concert details with their friends via Facebook, Twitter and email. Check it out in iTunes for iPad and iPhone.