Here are some related posts – or you can search with appropriate terms for your setup…
following referred to by Amy Lauterbach posts above:
http://adventurealan.com/iphone4gps.htm
http://dl.dropboxusercontent.com/u/15393086/BPL/iPhoneGPSapps.htm
I have AT&T iPhone 5 w/Gaia GPS – had iOS 6 and was happy. Went to iOS 7 recently and am very displeased with battery drain in spite of doing everything to limit it. Per Amy posts, Verizon version is much easier on battery.

