What is a viewer to do?

Two Cambridge enterprises have answered the call, developing free digital tools to help voters navigate the cacophonous flood of information this presidential campaign and separate facts from falsehoods.

The Super PAC App, created by a digital production company called Glassy Media, would allow truth-seeking viewers to quickly access information about the ad by holding their smartphones up to the television. Using audio fingerprinting technology, the mobile app recognizes the ad, identifies the group that paid for it, and allows the user to explore the claims of that ad.

Another Cambridge entity, Nimblebot.com, will launch a web platform Thursday that will display presidential campaign ads with tags that mark each claim as “true,” “false,” or “ambiguous” and provide links to the research behind those assessments.

Their motivation, the developers say, is neither profit nor partisanship, but a desire for transparency. They see this as especially relevant in an election season expected to be inundated with campaign ads sponsored by super PACs: political committees unaffiliated with any candidate that are allowed to raise unlimited funds from virtually any source and spend this money to influence elections.

“Your TV is going to be screaming political ads at you, especially if you live in a swing state,” said Dan Siegel, 28, who co-created Super PAC App, which is scheduled to be downloadable for free in time for the Republican National Convention on Aug. 27. “To help users or voters to learn a little bit more about the information that is being thrown at them: We think that’s incredibly important.”

Nimblebot.com, which normally designs interactive events and Web applications for such clients as Samsung and Showtime network, has taken a time-out from its profit-making ventures to develop Reactvid.com.

“We are extremely concerned about the way that people are being communicated with as the campaign approaches,” said Nadeem Mazen, 28, chief executive of Nimblebot.com. “It seems like the super PACs have a huge amount of say and a huge amount of sway. And it’s time for all of us to do something about it.”

Siegel, whose project is funded by a Knight Foundation grant, said he and his cofounder, Jennifer Hollett, got the idea for Super PAC App while they were graduate students taking a class at the MIT Media Lab on how people use a “second screen” — smartphones, tablets or laptops — while they watch television.

Both Super PAC App and Reactvid.com will rely on the premise that TV viewers are increasingly using that second screen to access websites that help them analyze, verify, or find out more about what they are seeing on the bigger screen.

There is evidence to back the notion: A recent Pew Research Center survey suggested that 22 percent of cellphone owners use their devices to check whether something they hear on television is true.

Whether these applications will be successful depends not just on the validity of the “two-screen hypothesis,” said Joshua Benton, director of the Nieman Journalism Lab at Harvard. A more important question, he said, is how many smartphone users will want to spring off of their couches, open the app, and use it while watching a political ad.

“All that happening in 30 seconds seems to me unlikely to catch on with a broad audience,” Benton said.

Another issue is how the facts are checked. Siegel said Super PAC App will connect users to “third-party, nonpartisan sources,” such as major media outlets, or fact-checking sites such as FactCheck.org or PolitiFact.com. But there is plenty of discord among American media audiences about which outlets are partisan.

“Some people think watching Fox News is ‘checking the facts’ against what The New York Times is reporting,” said Robert Thompson, a professor of television and popular culture at Syracuse University. “Often, checking facts is a matter of interpreting information.”

Mazen said Reactvid.com will address the problem of objectivity by relying on volunteer researchers of diverse backgrounds and beliefs — “Republicans, Democrats, Independents, non-affiliated, fed-up” — to do its fact-checking. He said Nimblebot.com will vet the researchers, and he is counting on “people on the left, right and in-between saying ‘listen, I can be objective, too.’ ”