To look for really nice EUC rides on gravel in Sweden, I recommend you use the Trafikverket Web service.
It gives you a good way to “plan my EUC ride sitting in the kitchen”. Then you can use other apps when actually riding. 
But for planning and for discovering the 300 000 km gravel roads in Sweden, it is outstanding!

  1. Choose ”Väguppgifter” in the first dropdown for ”Dataslag”
  2. Choose ”Slitlager” in the second dropdown for ”Dataslag”

    now the gravel roads are marked in green!

    you find NVDB at https://nvdb2012.trafikverket.se/SeTransportnatverket