Google Maps is the only maps app you need on mobile.

Google Maps is the best mobile mapping application. Period. It has the best and most accurate location data along with handy turn-by-turn navigation. Google Maps comes included with most Android phones and you can download it to the iPhone as a separate app.

If you have a Windows Phone, BlackBerry, or other device, you can get Google Maps through its mobile website.

Available for iOS, Android, and through a Web app.