Super PAC App is a useful tool for measuring the length of a politician's nose

FORTUNE -- Alex Fitzpatrick's piece in Mashable Wednesday about Super PAC App -- a free application for Apple's (AAPL) iPhone, iPad and iPod touch -- pitched it as a tool for finding out who paid for a particular political ad.

It doesn't really do that, because current campaign financing laws allow donations to political action committees to be unlimited and anonymous.

But what the app does do is point users to independent articles and sites like PolitiFact and FactCheck.org that test the truthiness of an advertisement's claims.

The app uses TuneSat, a technology developed to spot unauthorized use of copyright music, to identify an ad by its audio signal. Just hold your iOS device up to the speakers  -- as you would with music apps like Shazam or SoundHound -- when a political ad appears and Super PAC will try to match the ad to its database.

When I tested the app on ads I found on YouTube, it only worked about half of the time. But when it worked, the claims testing function was both useful and relatively nonpartisan. I learned, for example:

• That FactCheck examined that a Mitt Romney ad that claimed Barack Obama had adopted "a plan to gut welfare reform by dropping work requirements" and found that "the plan does neither of those things."
• That FactCheck found the Priorities USA Action ad that linked Mitt Romney's Bain Capital to the death of a woman "misleading on several counts," and PolitiFact called the PAC's claim that the ad did not mean to imply that Romney was responsible "preposterous."
• That PolitiFact examined several American Crossroads and Romney Campaign ads that took the President's "you didn't build that" quote out of context and found they pinned the Truth-O-Meter all the way to "False"

You can download Super PAC App from the iTunes store here. Did I mention that it's free?