Google turn by turn API (iPhone)

I can't find API from Google which provides turn by turn based directions. Just wanted to 开发者_Go百科make sure if this type is even public? If not, what are my alternatives on iOS?

Thanks!

Have you tried Googling "Google Maps Directions API"? This is easy to find on Google or in the Google Maps API homepage.

http://code.google.com/apis/maps/documentation/directions/

"Each element in the steps array defines a single step of the calculated directions. A step is the most atomic unit of a direction's route, containing a single step describing a specific, single instruction on the journey. E.g. "Turn left at W. 4th St." The step not only describes the instruction but also contains distance and duration information relating to how this step relates to the following step. For example, a step denoted as "Merge onto I-80 West" may contain a duration of "37 miles" and "40 minutes," indicating that the next step is 37 miles/40 minutes from this step."

When I implemented this on Android, I passed a URI formatted string with an address to the OS which called the included turn-by-turn navigation which I recall was a 3rd party api (but shipped with the OS). Now that I'm developing iOS, I too would like to identify a solution on iPhone. As far as I can tell so far, there is no similar API for iOS (yet). I actually hope that I'm wrong here.

Hope this helps.