Finding the best carrier coverage on the go

A new iPhone app from Root Metrics lets you research carrier performance for your home, neighborhood, commute, or workplace right on your iPhone.

Editor's note: This app is available only in the United States.

Though CNET's always been here to rate the latest cell phones, your handset is only half the story in the search for a great wireless experience. Strong coverage from your carrier is equally important, but finding that reception, and keeping it, isn't easy.

That's why we've partnered with Root Metrics to create a unique tool that can help you check reception strength and make a carrier decision. You might have already discovered the tool when browsing any CNET cell phone review (look for the "Check coverage in your area" link next below the CNET editors' rating), but now you can check coverage right where you stand with Root's new iPhone app.

Like the online coverage tool, the app uses a Google Maps mashup to show carrier strength in your area. The color code is easy to remember: green and yellow are best, orange is in the middle, and red and black are worst. And like its Web-based counterpart, the app tracks three data points for the "big four" national carriers. The Root score represents the carrier's overall network performance, the voice score shows the voice signal strength for your location, and the data score measures the power of the carrier's data network.

To get information on your specific location, just click on the purple pushpin that represents you. In the pop-up window, you can check the three scores for each carrier and compare how the carriers fared against each other. You also can access the signal strength in decibels for where you're located and check the average download and upload data speeds.

The Root app also allows you to run your own tests and report any problems with your network. When you click on the "Test" icon on the bottom of the screen, your phone will measure the voice signal strength and upload and data speeds at that time. If you're having reception troubles, just click on the "Report" icon and tell Root if you've had a dropped call, a poor signal, no Internet, or slow data. Each time you run a test or file a report, Root will automatically record your results and factor them into the overall ratings for your area.

The Root app is available now for free in the iTunes App Store (search for "Cell phone coverage map" if you're having trouble finding it). I encourage you to download the app to help you better measure carrier coverage and help Root improve its data. And don't worry, Android users: an Android app will be coming soon.

The map uses a color code to show signal strength for your location (purple pushpin) and the surrounding area. Screenshot by Kent German/CNET
With the test feature you can find the voice signal strength and the average upload and download speeds for your location. Screenshot by Kent German/CNET