Are people using the Nokia Here app? I have it on my phone, but I haven't used it for navigation. At one point I was looking into experimenting with pulling the 3d building models.
It is excellent. Its offline navigation is way better than Google. A always use it when I travel to another country.
Here isn't Nokia anymore. They sold it to Audi, BMW and Daimler in 2015.
I used it exclusively for navigation on a windows 8 phone (and it was reliable and a good experience), but it seems they didn't release a windows 10 mobile version when I upgraded.