I used OrganicMaps for navigation from the UK through France, Germany, Switzerland, back into France and then Spain last year on a 2 week enjoyable camper van trip. It can take a while for routing changes if you ignore it and decide to drive elsewhere, and I don't really use the voice alerts (I just have it on my phone on the dashboard via a magnet), but all in all it worked really well.

Although I would like speed limits shown in MPH in the UK, OrganicMaps' KMH limits were useful on the Continent.