I have CoPilot for the US and for Europe. Ive used it in remote parts of Arizona, Utah, Oregon, upstate New York, and New England successfully, even in areas with zero mobile signal.
In-app purchases allow you to buy international maps, and Ive used CoPilot on road trips in Ireland and Germany.
I find that CoPilot is the most reliable navigation app in situations with poor or zero mobile signal. CoPilot was a lifesaver while driving in Germany; even when I did not understand German road signs, CoPilot got me where I was going, and we didnt get lost once.
Pros: The app is highly flexible, and allows you to create complicated routes and save them. It works offline. It has optional speed warnings.
Cons: the list of Points of Interest, especially in Ireland, is not as comprehensive as, say, Google.