Available on iOS, Android, Windows phone, Samsung devices and has a webapp. (Announcements recently stated by new owners support for Windows phone will be dropped in the future).
Ranked in these QuestionsQuestion Ranking
Pro Downloadable offline usage
One can download maps for virtually the whole world. You can download maps for offline use by continents, countries or by state.
Pro Speed Alert notification
The app can alert you with beeps when you are speeding (a user adjustable threshold) over the current speed limit.
Pro Web version for planning/storing favorite places
Specially good for traveling.
Pro Great Lane guidance and Speedway EXIT images
Con No lane guidance
Lane guidance is very helpful in large urban cities or on the interstate, it's easy to feel lost and miss a turn without lane guidance.
Con POIs not as current as competitors
Points of Interest tend to not to be as up to date as other online apps are. Often another app has to be used in order to look for interesting places, or connect to a hotspot.