This app was mentioned in 1 comment, with an average of 2.00 upvotes
I recommend Navmii USA. It has offline maps that can be downloaded by state and good turn by turn navigation. They use map data from openstreet.org/ https://play.google.com/store/apps/details?id=com.navfree.android.OSM.USA
For other countries they have Navmii World. https://play.google.com/store/apps/details?id=com.navfree.android.OSM.ALL