Google Maps is probably a favorite tool for a lot of people. I like to use it mostly for planning routes but I sometimes use it for navigation.
Recently for the 2 meter Simplex contest held by the SLSRC and the ILQP I used Google Earth to plot my operating locations by adding pin symbols and labels.
You save the KMZ file from Google Earth to your Google Drive and then follow these steps.
Open Google Maps
Select "Your places"
Select "Create Map" at bottom left
Import KMZ file from your Google Drive
Now you should have a map similar to this one.
I also used this for the ILQP. This time I paired the phones bluetooth with my truck radio. Now I have turn by turn directions coming through the trucks sound system. It worked great!