I've used the Google Earth app on my laptop for all 20 of the published Sgt. Dunn Novels, and the one in progress. Nineteen were in WWII and two are in the Korean War. I use yellow pins for Dunn's and Saunders' locations, and red for the Germans. I can view users' uploaded photos to get a nice look around the area.
The app has excellent tools including a measuring stick that gives distance and compass direction, a path drawer that I use to measure distance not in a straight line, and others.
