HERE is an online and offline map and navigation app created by Nokia, it is free to download and use.
Ranked in these QuestionsQuestion Ranking
Pro Wider availability of downloading maps from various countries
HERE maps allows users to download maps from more than 200 countries.
Pro Interactive 3D maps
There are interactive 3D maps for shopping areas and airports for 70 different countries around the world.
Pro SD card support
Pro Save maps for offline use
HERE allows users to save maps to their devices storage in order to allow offline usage of the app anytime.
Pro Voice-guided navigation
HERE has voice-guided turn by turn direction built into the app and is even usable when offline.
Pro Includes public transport routing & schedules
Has train, ferry, bus etc. routes and schedules for many cities. The routes are overlaid on actual maps (spatially correct, vs the typical simplified diagrams of public transport networks) which I find reassuring and useful when exploring new locations. Also shows the schedules for next few services for any given station/stop. I'm not sure how accurate the schedules are though - they were incomplete for the small town where I live, but seemed more complete for major cities.
Pro Great smartwatch companion app
Excellent companion app allows navigation from your paired Samsung Gear S3 smartwatch. Has clear turn-by-turn instructions, vibration alerts at intersections, and zoomable location map (using rotating bezel). (Smartwatch app works with phone app and is not standalone).
Pro Has multilevel floor layouts for many airports and large shopping centers
Many airports and large buildings have an icon on them which, when tapped, opens up a 3D view of the floor plan with labelled locations of services, shops & transport etc. Includes an index for selecting each level of the building.
Con Map file size
Map downloads are huge in size, ranging from a few hundred megabytes, to a couple of gigabytes, depending on the size of the map being downloaded. Luckily, the app can be set to store them on external SD memory.