Map Navigation Application that Builds on Top of Google Maps
Navigation implies turn-by-turn directions. When iOS 4 was announced, Apple stated that background navigation was one of the "poles in the tent" (one of the big 6 new features that made up the iOS 4 upgrade). However, per their licensing agreement, developers are NOT allowed to leverage Google Maps when building driving direction applications. They must build off their own data. That is why all the other apps you see (TomTom, Navigon, OpenStreetMap, etc.) all look unique, and have their own data.