There are many Apple apps but this by far has to be one of my faves. iConcertCal is a free iTunes app that collects information and monitors music from your iTunes account and tells you when the artists you are listening too will be playing - live and in person. Personalized to your city, it will generate upcoming concerts in your city. Available for the US, Canada, and the UK. Not only will it monitor your fave artists, once a concert is found in your city, you can purchase tickets directly from the app for it. Now only if would pay for the ticket..