Nowadays, we'd argue it's virtually impossible to get lost on the road with GPS technology built into most every smartphone. With the right hardware in place, a good driving app offers turn-by-turn navigation features that once belonged solely to dedicated GPS units. Here's a list of our favorites for various mobile operating systems to help you get from point A to point B without asking for directions...
iOS
Navfree GPS Live
There are two categories navigation apps fall into: live positioning and preloaded maps apps. One requires an online connection to refresh/update maps, while the other is untethered because all the maps have already been loaded. Navfree GPS Live has the capacity for either. When in wi-fi range routes can be downloaded ahead of time to save on data costs; Navfree gathers open source maps and uses that information to your advantage. Classic features such as turn by turn, spoken or on-screen instructions are all available, covering a wide range of regions, and also iPad compatible if your co-pilot in the passenger seat wants to help out. Free - $2 Ad free
MotionX GPS Drive
For more premium features, MotionX gives users live traffic updates, full music control, and consistently up-to-date maps. The app does require a live and consistent data connection, so this app is best used where online connections are plentiful and dependable. What we love about MotionX is how integrated with the rest of the phone it is with access to our contacts addresses, music control, Twitter and our e-mail. Users can even make in-app calls! Of all the paid services, we believe this one provides the best value. $1 for the app - $3/30 days - $25/1 year
Android
MapQuest
For those who were wondering, MapQuest is still alive and kicking. The once king of directions now lives as an Android app that you can interact using voice prompting. MapQuest even talks back by giving turn-by-turn directions and corrects its bearings should a wrong turn be made. Locations can be saved for later reference. Places of interests such as restaurants, hotels, gas or shopping can be searched and marked on the map or shown when in the vicinity. Unfortunately, this is an app that requires a constant internet connection, however the price is absolutely right. Free
CoPilot Live
For those who prefer the safe route and want the maps stored at all times, CoPilot Live is a beautiful app that covers a wide range of ground for a price. A great attention of detail is added to its 3D driving view with signposts and lane indicators to clarify how roads flow. We love how points of interest are indicated on the map and can be called with the tap of the screen should you wish to inquire for further details. Additional services include LiveTraffic ($10 for a year) and live weather updates. $9.50 for US, $20 for North America, $40 for United Kingdom + Ireland and $85 for Europe
Windows Phone 7
Navigation
For the best of both worlds, Navigation has all bases covered. The GPS version can create a travel itinerary with downloaded maps over wi-fi or use the wireless connection as life happens. Audible turn by turn directions are present as well as ETA predictions based on distance, speed and traffic wrapped in a delightful interface. Should you choose the preloaded map variation, Navigation also has a great deal of locales to choose from. GPS app - $5
Navigon
Navigon has several features that make it worth consideration despite the hefty pricetag. On top of the audible directions and traffic warnings, it also has a speed assistant which can help you keep an eye on how fast you are going; especially handy when entering areas with sudden dips in speed limits. What else is handy is the take me home button which always leads you back to home sweet home. The lane assistant (pro) feature advises drivers which optimal lane to stick to, alongside informing about upcoming construction or traffic issues can be pre-emptively countered before you even start to see any orange pylons by shifting to the best lane. It's not perfect, but it's probably the best WP7 option out there.
$50 for US, $100 for Europe
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Bad list.
MotionX GPS Drive does allow you to pre cache the maps needed for a particular route.
It should also be noted is that all phones use assisted GPS. It has been my experience that my iPhone 4 DOES work for GPS when there is no signal, however, it is much slower to lock, less accurate, and doesn't update very often. Of course, if you are in an area with no signal, chances are good that nothing of interest is going on so you don't need all that, but worth noting none-the-less.
MapQuest is also available for the iPhone. It also requires a data connection. But given the price (free) its a great option for turn-by-turn voice GPS directions. I also appreciate that you're not loading hundreds of MB of maps on your phone to use it. With all of the free apps, I find you're better off finding the address of a business in other tools (google, yelp, etc) and then pasting into your GPS--but that's a fine tradeoff for the price.