HQ Trivia was once one of the hottest apps around, but just a couple years later it's been killed off.

HQ Trivia is shutting down and is laying off its 25 full-time employees. In an email obtained by CNN Business, HQ hired a banker to help it find investors and it "received an offer from an established business", but that deal fell through.

"Unfortunately, our lead investors are no longer willing to fund the company, and so effective today, HQ will cease operations and move to dissolution," said HQ Trivia CEO Rus Yusupov in the email.

Yusupov posted a tweet today after news of HQ's shutdown broke, saying that HQ "didn't get to where we hoped" but that it "did stretch the world's imagination for what's possible on our smartphones."

With HQ we showed the world the future of TV. We didn’t get to where we hoped but we did stretch the world’s imagination for what’s possible on our smartphones. Thanks to everyone who helped build this and thanks for playing.

— Rus (@rus) February 14, 2020

HQ Trivia was huge in late 2017, getting millions of people to log on to a live trivia show on their smartphones twice a day for a chance to win cash. That popularity eventually faded, though, and popular host Scott Rogowsky left the show.

HQ did try some new things, including a photo challenge game called HQX, but it was never able to regain that popularity it once had. 

Did you ever play HQ Trivia?