A screenshot of CarrierCompare, which measures the network quality of Verizon, Sprint and AT&T systems

NEW YORK (CNNMoney) -- A new app hit the iTunes store Friday morning that your carrier probably isn't too thrilled about.

It's called CarrierCompare. Developed by Boston-based startup SwayMarkets, it allows you to see which carrier offers the best service for your iPhone in any given location.









The crowd-sourced app is simple to use. After you touch the start screen, the app takes about 15 seconds to analyze your network for signal strength, response time and speed. It then compares your result with other nearby results on the other two national carriers' networks.

The display is intuitive, telling you where your carrier ranks compared to the competition.

Sounds pretty simple, right? But iPhone carriers Verizon (VZ, Fortune 500), AT&T (T, Fortune 500) and Sprint (S, Fortune 500) have successfully kept that information out of the public's view -- until now.

Carriers rigorously test their networks and their rivals' networks, hiring third-party surveyors to perform comparisons. However, those surveys are almost always performed under non-disclosure agreements.

Each carrier provides its own coverage map to customers, and some even offer a street-level view. (Here are the maps for Sprint, Verizon and AT&T.)

But that still doesn't give users the kind of precise detail that CarrierCompare provides -- and the carriers certainly don't offer up direct, pinpoint comparisons against the competition.

"There is an imbalance of information out there," said Amos Epstein, founder of SwayMarkets. "Each carrier knows its own network and hires people to drive around in trucks to measure its rivals' service as well. But they haven't gone as far to release data that's tangible and useful to the consumer."

Carriers also get that data from apps they make handset manufacturers install on their devices. Sprint and AT&T use an app called CarrierIQ, which sends that kind of information -- and more -- back to the carriers.

After landing in the crossfire of a giant controversy around the secrecy of that data, CarrierIQ urged its carrier customers to release that information to consumers. So far, none have done it.

Calling CarrierIQ "a cautionary tale," Epstein said CarrierCompare is designed to make visible metrics that are typically hidden from consumers' view.

The app tracks three data points.

"Signal" represents a granular, numerical interpretation of service bars, which gives a more accurate reading than a one-through-five bar graph representation.

"Response" measures how long it takes for the network to respond to a request. It's an important metric for Internet use, such as Web browsing, posting pictures to Facebook and downloading apps. A lower response time indicates a better result.

"Speed" is in indicator of how much information the network allows your phone to download in a second. Good 3G service can be as fast as 2 Megabits per second during non-peak hours, and 4G service can be more than five times faster than that.

Here's the catch: The app is only as good as its crowd-sourced data. SwayMarkets has a starting data set pulled in from its previously released NetSnaps app, but CarrierCompare will only become really useful if a critical mass of people adopt it.

Right now, the app only performs the one function -- touch and compare. But within a few weeks, the SwayMarkets team said CarrierCompare will become much more dynamic.

When the second version is released, the app will allow users to collect network comparison data in the background, while other apps are in use. That will let the app detect network information throughout a user's day and produce an analysis on the best carrier for that specific users, factoring in things like their typical commute route and work location.

That "set it and forget it" capability will also allow users to check in every once in a while and see how their their network is holding up

CarrierCompare is on sale for $1.99, and an ad-supported version is available for free. The app is only available on the iPhone for now, but the SwayMarkets team said Android versions are in the works.