Not an app, but a great website. I have been using it forever now. It is being maintained and improved by an active group of developers who work closely with everyone over on ADV Forums, so it is really moto-centric. The improvements over the last few months have been awesome. And it begs for the user to get in and play with the route. Oh, and it's Free. And you can export in most of the popular formats for import into different GPS units. It is my goto for routing, then I use an app on my phone that pulls the route directly from the website without having to export/import.
Routing site: Furkot Planner
The app I use on the phone is Scenic (iOS Only right now, search App Store, I dont have a link).