I really like OnXmaps. what you are referring to is there mobile service. OnXmaps in and of itself is like google earth but with a ton more hunting specific overlays which I really like. However the mobile version you do have to save the maps to your cell phone and then switch you cell phone to airplane mode when using it in place of a GPS. I like it that my phone has a much larger screen than my GPS when using OnX however you better not forget to charge it up everyday!