Many months ago I received a review copy of G-Map for the iPhone. It had its own maps and turn by turn directions, but no voice guidance, and North was always up. Apple was limiting nav apps at that time, and I had real trouble with G-Map. I couldn't load it on my iPhone. It kept locking up about halfway through the process. Extensive back and forth with the developers in Japan came to nothing, so I gave up. Finally, last April, my colleague Steve Sande was able to load it, and reviewed it for TUAW.
Now, with iPhones having new hardware and new software, G-Map [App Store] works and is certainly a competitor to the subscription-based AT&T app. You buy G-Map in one of several editions. G-Map West, at US$34.99, covers the Western States, and G-Map East covers, you guessed it, the Eastern U.S. It is also priced at 34.99. It gets a bit tricky, because some states like Illinois, Michigan, Tennessee and Wisconsin are split. If you travel all around those states you will probably want both editions.
There is also a California edition for $19.99, and one at the same price for New Jersey and New York. Versions for Canada and Europe are coming. All the G-Map modules require iPhone software version 3.0.
So how does it work? Pretty well, but with some caveats. It's accurate at getting your position. The voice directions are quite audible, especially compared to the distorted AT&T app. The on-screen display gives you your speed limit, distance to your next turn, distance to destination and time to destination. It also plots major intersections in a very detailed 3D view, which is helpful. This works in the largest 185 metro areas.
Another plus is that all the maps are on your phone. If you slide out of AT&T's service area the maps are still there; in contrast, the Telenav-based AT&T Navigator app will not work if you don't have data coverage, as the maps are downloaded on-demand.
There are some downsides. The POI database is pretty thin in smaller towns. From Southern Arizona it couldn't find the Phoenix Airport. It probably would have found it when I was closer, but even a POI search didn't bring it up. As I was sitting at a long established car wash, it said no car washes were nearby. It did better with restaurants, banks, and hospitals. Like the AT&T app, there is no landscape mode, and you can't get access to your address book, which is just plain silly.
It looks like the database, which comes from Navteq, has some errors, as do all such systems. Navigating to a restaurant, G-map reported it was on the left, when it was actually on the right.
Unlike the AT&T Navigator, G-Map has no real time traffic, but it does provide info from Navteq's traffic statistics to predict trouble areas.
Even with some weakness, G-Map is a worthy competitor to the AT&T iPhone app. If you have the room on your phone (G-Map West is 824 MB), you can navigate without worrying about cell network access.
It's cheaper than a monthly subscription would be over time, although there is no word when maps will be updated and what the cost will be. If the G-Map developers clean up the POI database, and add a lot more to it, I think they may sell a lot of apps. As it is, for getting to places where you know the address, it works about as well as the AT&T Navigator at a fraction of the cost. Of course more choices are coming, including the much discussed TomTom app, so you may want to wait it out and see what other offerings come along.
Here are some screen shots that show some of the major features: