The best map app by far is maps.me. For someone like me who doesn’t run a WLAN, being able to download the maps through my browser and transferring them to my Samsung S5 via USB is a huge plus.
What you then have are any maps you like, completely offline without having to be afraid of roaming charges. Maps.me offers fast and detailed maps for everything that are updated regularly. If you download a map plus “routing”, you can create routes. Besides that, you can of course bookmark favourite locations, enjoy offline searching with auto-suggestions and an auto-follow GPS mode. Perfect.