OsmAnd - Global mobile map viewing and navigation for online and offline OSM maps
AllTrails - Explore over 50,000 trails, reviews, and photos. Share them…
MAPS.ME - Fast, detailed and completely offline maps for mobile devices
TrailLink - TrailLink is the best-in-class trail-finder Website and app that provides detailed descriptions, photos, reviews to help hikers and outdoor enthusiasts plan their trips.
HERE WeGo - HERE WeGo - Maps - Routes - Directions - All ways from A to B in one
GPSies - With GPSies you can view and download tracks which have been recorded by a GPS device.