With just days to go until Election Day, a slew of apps are connecting voters who want #NeverTrump and are willing to make a trade — even if they’re not planning on supporting Hillary Clinton.

These apps, among them #NeverTrump and Trump Traders, connect Clinton supporters with third-party voters in swing states — so a Clinton supporter in, say, California, could trade their vote with a Jill Stein supporter in Florida. The third-party voter could rest assured that their candidate got a vote without worrying that they’re splitting the vote and strengthening Republican candidate Donald Trump’s chances in a battleground state.

“It’s unfair that third-party voters are told their votes are ‘votes for Trump’” Maggie T., a 31-year-old author of young adult books from Delaware, told The Post in an email. “With vote swapping, everyone can cooperate and have their voices heard.”

Maggie, a Hillary supporter who read about the app online, connected with someone who lives in Pennsylvania and wanted to vote for the Green Party.

“It felt very neighborly,” she wrote, adding that they chatted and agreed to swap within five minutes.

In an election year fraught with worries of fraud and voting scams, experts told The Post that the app is legal.

“It doesn’t sound any different than me calling up my uncle in Florida and persuading him,” Thomas Keck, a political science professor in the Maxwell School at Syracuse University, told The Post. “It’s like if you don’t have an uncle in Florida.”

But since voter laws vary by state (you can’t take a voting booth selfie in New York, but you can in Utah or Louisiana), vote swapping sounds like it would be illegal. But, according to the 2007 California appeals court case of Porter v. Bowen, it’s not.

“This is how politics work,” Jamie Raskin, a lawyer who wrote about vote trading in his book “Overruling Democracy: The Supreme Court v. The American People,” told Mashable. “People form coalitions to advance future goals.”

Here’s where the legal precedent comes in. During the 2000 election, “Nader Trader” websites connected Green Party and Democratic Party voters in order to swap a Ralph Nader vote in a swing state for an Al Gore vote. But a week before the election, former Republican California Secretary of State Bill Jones sent a cease-and-desist letter to Alan Porter, the operator of votexchange2000.com. Similar websites like vote-swap2000.com and nadertrader.org also shut down.

Porter, joined by the American Civil Liberties Union and the National Voting Rights Institute, sued Jones for violating Porter’s First Amendment rights. The case went to the California Ninth Circuit Court of Appeals, and the resulting decision deemed voter swapping completely legal and protected speech under the First Amendment.

Keck agreed that as long as there’s no bribery or exchange of money, these apps are “just a platform for facilitating conversation between voters.”

“I wish we had this in 2000 in New Hampshire and in Florida,” Tad Devine, a senior adviser to Gore in 2000, told USA Today.

While the Nader Trader websites didn’t make an impact in the Electoral College, they certainly had the potential to: The 2000 election was decided by a mere 537 votes.

Amit Kumar, founder of the #NeverTrump app, told USA Today he estimates more than 10,000 people have used his app since it launched in early September.