Another program you may be interested in for kicks is Motor Dash. It shows you the actual angles you lean when cornering as well as your speed. gRide is another that will tell you the acceleration gForces when you ride to see if you have a smooth acceleration and whether you keep a constant throttle application.
I looked at Navigon, and a few others (Whereis, NavFree etc), but still keep going back to the paid TomTom that I purchased some years ago on the iPhone 3G. I also used Navigon on smart phones years ago and found it wasn't really that intuitive for me after having used TomTom & Garmin. My personal opinion, but some blokes probably enjoy it.