I'm a big fan of GPS navigation devices. Actually, I depend on them. It's therefore natural that on my iPhone 3GS you'll find both the newest turn-by-turn GPS navigation applications, the $70 Navigon and the $80 iGo My Way. Both have just recently been released to the App Store. (In my car I also have the Tom Tom One XL.)
After about a week of using the iPhone apps in the San Francisco Bay Area, as well as in a few other states, here are my impressions.
First of all, both Navigon and the iGo can turn your iPhone (3G or 3GS) into a decently dependable GPS navigator. They both take about 15 seconds to load on my iPhone 3GS and about the same time to lock in with a GPS signal when outdoors. This is much faster than the Tom Tom, which can take up to a minute or two. Overall, the iGo My Way seems to pick up the signal faster than the Navigon, but it also loses the signal more easily, especially when in a big city with lots of high-rise buildings.
My biggest disappointment with both is that they don't offer real-time traffic updates, which you can get anywhere in the States with Google Maps.
Both apps offer beautifully rendered 3G maps that can be viewed vertically or horizontally, and a very convenient way to enter a new address or find a point of interest (POI). They come with good databases of POIs, too. I was in a few rather remote areas and was able to find what I needed. However, the database is not very updated--twice, both apps took me to restaurants and bars in La Cross, Wis., that were no longer there. Unfortunately, you can't tab on the listed POI to call its phone number, which defeats the main purpose of the iPhone, which is, after all, a phone.
The maps of both apps could also stand to be updated, as I couldn't find the same address here in the Bay Area on either the Navigon and the iGo My Way and this particular address has always appeared in several car GPS devices I've owned. It seems to me both apps share the same slightly outdated maps for North America.
Navigon and iGo My Way can load and function with the iPhone's music playing in the background. This means you can still listen to music (if your car has an auxiliary jack) while having the apps' audio driving instruction on. None of the apps, however, have built-in iPod controls, so you'll have to exit when you want to skip a song, etc.
While the audio instruction works when describing when to turn, which lane to stay on, and so forth, none of the apps offer text-to-speech. The Navigon, however, is able to read the name of freeways, such as, "Take the next exit to 580 West," while the iGo can only say, "Take the next exit."
The Navigon also beats the iGo My Way with its capability to pull addresses from the phone's address book. As someone with a pretty bad short-term memory, I found the lack of this feature in the iGo a deal breaker. The address is already on the phone; it doesn't make sense to have to type it in again.
To make up for this, the iGo does come with a lot more customization than the Navigon. Take the voice, for example. While you're stuck with one female American English voice with the Navigon, you can pick from a dozen with the iGo My Way and between three languages: English, French, and Spanish. The iGo also lets you change the shape of the onscreen image from the generic arrow to a car, taxi, truck, and more.
When an incoming call arrives while using either application, you can answer the phone like usual. The moment you hang up, the apps will automatically relaunch and continue with the existing navigation. You can also exit either app anytime and expect to resume the navigation just by launching the app again.
Both the Navigon and the iGo My Way drain the phone's battery pretty fast, each in about 4.5 hours when running nonstop on my iPhone 3GS. Also, the phone is sort of warm when either app is running. If you plan to use it as a primary GPS device, you should definitely get a juice pack or car charger.
Overall, both the Navigon and the iGo My Way are a great addition to the iPhone, especially for those who travel a lot. Personally, I prefer Navigon because it works with the phone's address book. But if you like customizing, the iGo is definitely a better choice.
Note that this is the initial release of both these softwares, and I have no doubt functions and improvements will be added with future updates. Personally, I would like to see both apps add real-time traffic update, plus the capability to dial up POIs, control the phone's music playback and, in iGo My Way's case, integrate with the phone's address book.