This app has a ton of features not found on many iPhone GPS apps. A very good coordinate converter, lots of export format options, intuitive options for creating waypoints (and a built in way to convert coords to the appropriate Google Street address). You can project waypoints with bearing/distance. Includes Google terrain layer as well.
There are two main disadvantages: From what I can tell (1) there is no tracking function and (2) there is no way to import common formats (kml, gpx, etc). If it were able to do that it might be the all in one GPS app. Im hoping they add these functions soon.
Zcel about GPS & Map Toolbox, v2.1.1