I just started using this iPad app, and I love it! It makes life so simple by finding awesome secret locations to shoot.
I think it's so useful for any photographer. Whether you're a landscape shooter, street photographer, even wedding photographers can use this to find interesting backgrounds for their pre/post wedding shoots.
I just made a review/tutorial on my new website:
http://ComposingTheMoment.com/stuck-on-earth-app/