Even with Apple jumping into the navigation sweepstakes, many iOS users will still need some kind of navigation app because they won't have an iPhone 4S
that Apple's new map apps requires. to enable the turn-by-turn feature of iOS 6's Maps app. [The Maps app itself will work on any iOS 6-supported device, but some features like turn-by-turn, Flyover and Siri support have more restrictive device support. –Ed.]
Still, there are people who want something free that has enough features to get from point A to point B without feeling they are a second class citizen. If you fall into that category, let me suggest you take a look at the MapQuest app, that has just been updated to version 3. The app already supported turn-by-turn voice directions, and has now added a new GUI, gas price information, live traffic cameras, better search, improved audio and landscape mode.
The result is a pretty full-featured app that looks good and generally works as you would expect it to. I gave the app a spin today to see how it compared to my favorite nav app from Navigon.
There were some issues I hadn't expected. When I searched for a destination about 12 miles away the app reported it couldn't find it because it was not within the boundaries of the view the app defaulted to. That's plain silly. I zoomed out, and then my search worked. The voice prompts are very clear, but I found the app too chatty. It sometimes told me 3 times about an approaching turn. I wish there was an adjustment to tame the verbosity.
The app worked fine in the background, alerting me to upcoming turns when my iPhone was on the home screen. Using the app requires a data connection, and theoretically, the maps should be very up to date. That wasn't my experience on my maiden voyage. A 3 year-old street next to a shopping mall was nowhere on the map, and the app kept reporting that I was on a street a half mile away -- odd.
Those criticisms aside, if you are looking for turn-by-turn navigation the MapQuest app has enough features to make it worthy of comparison to, some of the paid apps. As you've read, it's not perfect, but if you were counting on Apple for free navigation services, and you don't have an iPhone 4S, MapQuest may be just fine for you. Hopefully, it will improve, and the recent upgrade to version 3 indicates MapQuest wants to keep developing and improving this app.