It's a random-number generator for up to five dice, with a UI that makes it look like the dice roll for about one second. The dice are SVG elements.
It's just like having a functional cribbage board, except you can't lose or break the pegs.
Because I can! Once I got into HTML canvas elements at my day job, I wanted to see how it would work to replicate the groundbreaking original video game. Imitation is the sincerest form of flattery.
If you like to code, at some point, you've just got to make tic-tac-toe. Nothing special about this. In fact, the beginning tutorial for learning React.js has the user make tic-tac-toe, only better than this. Still, here's a fully functional tic-tac-toe game if you care to play.