Iowans are casting the first votes of the 2016 presidential campaign Monday night, and caucus results will be reported by Microsoft with a system it's describing as "the future of civic engagement technology." But not everybody is enthusiastic, with Sen. Bernie Sanders' team in particular expressing doubts.

Microsoft has built an app, developed in partnership with Interknowlogy, that lets authenticated caucus chairs report local results to party headquarters. The app runs on iOS, Android and Windows and comes in both Democratic and Republican versions.

Before, caucus leaders would report results through telephones and other systems, but this was open to human error, as in 2012. Microsoft is touting its system's error-detection abilities to flag any results that seem incorrect. The results are stored in Microsoft's Azure cloud and sent to media outlets immediately after approval.

The pressure is on for Microsoft. Any slipup has the potential to not only hurt the company's reputation, but fundamentally alter the balance of the entire election race.

In 2012, the public was told for weeks that Mitt Romney had won the Iowa Republican caucus in a narrow victory, until a final tally showed that Rick Santorum was the real winner. The mistake may have robbed Santorum of vital momentum that could have changed the course of later primaries. Romney went on to secure the nomination.

It sounds like a great deal, especially considering the app is free, but Sanders' campaign is asking why Microsoft is involved in the first place. Pete D’Alessandro, head of Sanders' Iowa campaign, told MSNBC: “You’d have to ask yourself why they’d want to give something like that away for free.”

Sanders' team has built its own backup reporting system that runs through an app and telephone hotline. The Hillary Clinton campaign has also built a similar backup system, just in case something goes wrong in the night.

Microsoft defended the application in a statement. "Microsoft is providing technology and services solely to administer and facilitate a neutral, accurate, efficient reporting system for the caucuses," it said.

A Quinnipiac University poll released Monday has Sanders polling 49 percent with Iowans likely to vote in the Democratic caucus, with Clinton at 46 percent. On the Republican side, Donald Trump has the support of 31 percent of caucusgoers, compared to Ted Cruz's 24 percent.