Skull button which is used to reveal the answer if no player gets it correct. It may work in other browsers or operating systems, but I have not tested it anywhere but my laptop.
This is what I used to develop/run the game.
If you end up using it and making any improvements, please consider sending me a PR. I can't offer any guarantees that it'll work though, since I have put absolutely no work into making it work anywhere but on my computer and for my needs. It has suited my needs well, along with my Wireless Eggspert buzzer system, and I've had requests that I publish the source, so that they could use it as well.
This is a simple PHP/Javascript Jeopardy-like board that I've used to run some trivia games in the PHP community.