https://buzzin.live/ is a free simple site where you can use a buzzer system in conjunction with my games. The host will log in first to create the game, and players will join in the same game using the unique room ID. You can use any device that can access the website through a browser, which makes this perfect for players to user their phones as a buzzer!
Have you used buzzin.live before? Let us know how it went below in the comments!