Navigon app for iPhone hits bumps

— -- Many applications on the iPhone take advantage of knowing where you are. But despite GPS (and other location-based technologies), it's only relatively recently that apps have appeared on the iPhone that promise to turn it into a true car navigation system. Meaning turn-by-turn directions via voice.

Navigon out of Germany claims to have the first "professional" solution for the iPhone 3G and 3G S, the Navigon MobileNavigator I've been testing. But the app is fraught with potholes, from sound issues to imprecise routing.

The $70 app ($100 after Aug. 15) covers the U.S. (including Puerto Rico), Canada, and the Virgin Islands. Navigon also sells a European version for $100 and an Australian version for $55. The Navigon app carries no monthly subscriptions, as is the case with the $10 a month you have to fork over for the AT&T Navigator (through TeleNav) iPhone app. The AT&T app is otherwise "free."

The field is about to get more congested. TomTom is readying a voice-navigation app for the iPhone that is due out later in the summer. Networks in Motion sells a $10-a-month app with real-time traffic called Gokivo + Yahoo Local Search. Other programs include Mobile Maps America ($80 from Sygic) and various regionalized $20 to $35 voice-guidance apps from Xroad called G-Map.

I tested the Navigon app in and around New York City and as far south as Maryland. Though I always made it to my destination, I was often frustrated en route. Sometimes, verbal instructions kicked in too late for me to make a turn, and sometimes I didn't get any verbal directions at all, an issue that a "soft reset" of the iPhone seemed to resolve.

Moreover, without "text-to-speech" technology — saying, "turn right on Main Street," rather than just "turn right" — it wasn't always obvious whether I had to turn at the block I was about to come upon or the one after that.

It's not all Navigon's fault. The iPhone doesn't let you run third-party apps in the background, so you can't take a call and continue to get directions. The app shuts down when a call comes in, and even though you're taken back to the route in progress when the call ends, you have to wait for Navigon to boot up again. Not a speedy process. If you don't know where you're going, heaven knows how many critical turns you might miss?