I've been researching navigation apps on the iPhone for a while and all my research kept bringing me back to the Navigon app. However, I wasn't willing to test the waters at the $50 price point, so I continued to get by with free apps like MapQuest and Google Maps. Fortunately, the App Store, like most other retail shops, knows how to throw up sales on Black Friday as well and I purchased the Navigon app for $29 last week.
Since it was a holiday weekend, it was inevitable that I would have trip over the river and through woods, so I'd have the perfect opportunity to test out my new navigation app. The Navigon app does lots of things very well and I was hard pressed to find ways I would improve it. More importantly, since Navigon runs on the iPhone, there are additional advantages over stand-alone navigation devices. Specifically, I use the USA Spec iPod adapter in my car to listen to music and stream Pandora from my iPhone through my car stereo. That also allows my iPhone to charge anytime it is in the car. By adding Navigon to the mix, I can continue to listen to music stored on the iPhone or through Pandora, and when driving instructions are announced, the music level automatically lowers to make it easier to hear instructions. If a phone call comes in, it's all still routed through the speakers and I can answer via bluetooth headset or speakerphone.
Navigon also offers a $20 "live traffic upgrade" which gives you lifetime traffic updates. On the ride back from Santa Barbara, I was alerted of SEVERAL traffic incidents which were along my route, but unfortunately, Navigon did not have any alternate routes to offer me. The ETA fluctuated wildly based on the traffic conditions, which is nice for setting expectations of what's ahead, but until I see case where my route gets changed to avoid the traffic condition, I'll wait to pass judgement.
Other Nav Features:
Landscape and Portrait mode
Freeway sign and lane "Reality View" so you know what lane to be in
Speed limit alerts
Google Local Search integration
Text to speech audio
Contact book integration
The only feature I really wish the Navigon had was the ability to receive voice commands so you wouldn't have to type in destinations. The Navigon app takes up 1.5GB on the iPhone so I'm assuming that means that the map data is pre-loaded onto the phone. That means if you lose cellular signal, you should still be able to navigate using the included maps.
Somehow the iPhone manages to help me push off a future car purchase because I can constantly add more "bells and whistles" to my commute without having to change my car. At this point, an integrated Navigation system built into the car would be a very tough sell for me considering the features available through the iPhone and apps like Navigon.