As always, a lot of this election hinges on Florida. And, it’s really close: Donald Trump currently has a lead of just 0.4 percent, according to Real Clear Politics, whereas the pollsters at FiveThirtyEight give Hillary Clinton a slight edge. A narrow win for Clinton could effectively lock things up for her.

That means that, if it’s doing as well as it claims it is, a new vote-swapping app could make a real difference.

Trump Traders is a project that pairs pro-Clinton voters from safely blue states with those living in swing states who want to vote third party. The gist is that the blue state voter agrees to go Johnson or Stein, in exchange for a swing-stater voting Clinton, where the Clinton vote will have a bigger impact. Third party gets the same number of votes, Clinton wins Florida, and everyone is happy (or less miserable).

According to one of the app’s creators, a man named John Stubbs who also co-founded Republicans for Clinton, more than 5,000 Floridians have pledged to support Clinton — over the third-party candidate they were planning to vote for. That’s a seemingly small figure, but let’s not forget that the 2000 election was famously decided by slightly more than 500 votes within the state.

Throughout the country, the app’s creators claim, more than 40,000 other voters have done the same.

There are a few caveats: we’re relying on Trump Traders self-reported metrics, and the app is based on the honor system — so there’s no way to prove that the people who claim they’re swapping votes are actually doing so.

According to Stubbs, who last week told Vocativ that the only “silver lining” of this election is the fact that individuals are willing to “cross the aisle…[in] thinking strategically about how to affect the outcome of the election for the good of their country rather than the good of their party,” Florida saw the biggest number of “new votes” for Clinton (presuming all traders keep their word). Ohio, Pennsylvania, Michigan, and North Carolina also amassed over 1,000 Clinton voters.

This method of partnering voters proved controversial in 2000 when Nader fans pioneered the practice using the still-infant web. Regardless, it has been deemed totally legal as a form of free speech.

The final vote was swapped just after 11:00 a.m. on Tuesday, showing just how down-to-the-wire some Americans were in their presidential decision-making this year.