The teacher hosts a game with a question set they either found it made, and each student joins on a device. They're givegiven the questions and selecting correct answers earns them something relative to the game.

The most traditional one is the one that was described here, where they are given every question in sequence and are awarded points for the accuracy and speed of their answers, but there is some great variety. There's a tower defense game where correct answers give you the currency to buy and upgrade towers, a "survivors"-like game where a correct answer is required to be given a choice of weapon upgrades and several variants on slot machine-esque games, where correct answers gives them a random bonus ranging across gaining score, multiplying score or stealing score from other players.

I like to use it with the kids whenever I require some rote memorization. Ie, we're reviewing terms we've used or will be using in a unit, or we're refreshing things they're supposed to have learned in previous years.

There's some great single-player options too, if you ever find yourself struggling to deal with rote memorization for any courses you'd take as an adult, too. While it's definitely targeted towards classrooms and kids, the games are imo substantially more engaging ways to memorize things that are in general hard to care about outside of a requirement for some job, diploma or degree.