Any opinions on the best Find a Point app for the Iphone

I'm looking for an "Iphone" app that has the best detailed in aerial and topographic switchable layers and you can enter in the state plane coordinate of the area your in, then it will direct you to it vie GPS for a minimal cost. I have the "findacontrol" and "coordinates" but still not there. One you can't enter the coordinates and the other you have to convert to Lat/Long and you get the basic road layer?ÿto get ya right in there!! ?ÿIdeally I want to enter a coordinate, track to it and also take measurements such as area and distance. Also work in low cell coverage area which I find is EVERYWHERE!!!?ÿ Any thoughts??