GPS apps for the iPhone

A flurry of GPS applications has appeared in the iTunes App Store to complement the iPhone's built-in mapping abilities.

In tests of several apps, we found that most work like a dedicated GPS navigation device, with similar menus and screen views. But none we've tested works as well as a good portable navigator. Navigation accuracy is not as good as we've seen in dedicated devices, and poor sound quality and low volume levels are common.

TomTom U.S. and Canada, Version 1.0
$100

Highs: Simple, easy-to-use interface and controls with bright graphics. Includes TomTom's IQ Routes, which factors in historic traffic patterns when it calculates routes. Good directions and onscreen information.

Lows: The most expensive app we've tested. An optional car mount and charger is said to improve accuracy but was not available for testing and will add to the cost. It lacks some features usually found on TomTom devices, including text-to-speech for spoken street names, emergency help, and lane assistance.

AT&T Navigator, version 1.2i.5, free download
$10 monthly fee

Highs: Simple interface, clean presentation. Includes text-to-speech, traffic reporting, gas-price information, and voice control for address entry. It's server-based, meaning that maps and points of interest are loaded dynamically as needed rather than built in. That means data is constantly updated.

Lows: The $10 monthly fee adds up fast. It lacks common GPS features, including lane assistance and reality view, and won't work without a cell signal.

Navigon Mobile Navigator 1.2.0
$70

Highs: Easy to use, with clear graphics and controls mimicking those found on portable Navigon GPS devices. Includes lane assistance, reality view, text-to-speech, and warnings for speed.

Lows: Lacks directions list and an exclude-road feature.

XRoad G-Map, version 1.3.1, map downloads sold by region
$20-$35

Highs: Easy-to-use interface, reality view, good graphics, multi-destination routing.

Lows: Adding other regions of the country means buying another app; no text to speech, poor iPhone integration.

Bottom line

A navigation application for your phone could be a good bet if you don't want to carry another device, but we think a good portable GPS remains a better choice for now.