Turn by Turn Navigation GPS devices for cars have been the main business for GPS companies such as TomTom and Garmin for several years. Both companies realised that having a GPS device in your car (a popular christmas present two years ago) and a also owning a large screen mobile device was a bit of a duplication. So they made App versions of their turn by turn products. TomTom sells its Turn by Turn UK and Ireland app on the iPhone app store for £59.99.
And so everything was happy in the GPS company garden.