In order to get directions, Google provides this nice URL:
Sample here...
How can I use the information that Google provides to get the same direction line on a
You will have to either use a web view with a Google map, or draw on the MKMapView with overlays. There are a couple of projects on GitHub that do this:
MKMapView
https://github.com/kadirpekel/MapWithRoutes
https://github.com/kishikawakatsumi/MapKit-Route-Directions