Monegros - The desert adventure

I've heard a lot about the Smugglers Route through the Pyrenees.
From what I hear it is a great trip with stunning scenery.

Route Pyrenees

It's on my to do list for sure.
This looks like a route that I am looking for. Can I assume that you are using the app wikiloc? Do I need to buy maps to use this app, just loaded route on phone but it had no mapping background..