SongKick for discovering/alerts of your favorite artists concerts
Just came across this app yesterday. Search iTunes for SongKick. It is FREE and awesome. The app scans your music library to automatically add your favorite artists, which you can edit and add additional artists after the fact, but this makes it very easy to start following or "tracking" artists immediately.
Basically what the app does is allows you to "track" or follow your favorite artists, and using locations which you select, or add by GPS location, shows you a very complete list of upcoming shows for your artists in your area. Multiple columns in the app give you plenty of viewing options, by locations, by artists, by date etc. The app also uses push notifications to alert you when your artists add tour dates etc. I have only been using the app for a day and I am very impressed. It has a great UI and functions great. It is free and anyone who loves music/concerts will love this app. Go get it