Mapbox has an excellent alternative map platform based largely but not entirely on OpenStreetMap data. Mapbox GL JS in particular is a joy to work with and extend. https://www.mapbox.com/ It's not free, but it's very easy to use and the pricing is roughly 1/10th of Google's when you get past the free tier: https://www.mapbox.com/pricing/ Mapzen used to be an alternative but sadly they shut down. However many of their…
Mapbox's maps look great, though I wish they had a generic product like Google Maps that I could use. Does any such general navigation app using Mapbox exist? Basically a vector OpenStreetMap with good search and routing.
As you see, it's not exactly built for this type of usage, but it is supported and the app is generally considered as the best alternative out there, so it might be worth a try!