OpenSignal

Learn how the four major cellular providers perform in your area with the help of OpenSignal's web site.  They also have smartphone apps to see how you're performing in real-time.  It will even point you in the direction of the closest cell tower, handy if you're on the edge of coverage and looking for a little better signal.

http://opensignal.com/network-coverage-maps/verizon-coverage-map.php