It's not really too similar -- it's a way for devs to determine which directions-enabled apps (Apple, Google, whatever) the user has installed and to kick over routing requests to them. But looks like a nice, lightweight library, too.
I was glad to see Apple make the changes to MapKit necessary to make this happen and am double glad to see MapBox taking advantage of it!
Now, if they'd only update their own iOS app! Their satellite images are beautiful, but their app is a mess.