Not everything on the site is a calculator. A chunk of it is just games — the kind you can open on one shared screen, or throw on a smartboard, with no app to install and no account to make. They fall into two neat camps: proper two-player strategy games you play against a person, and "review games" where you load your own questions and the game is the wrapper.
Two-player strategy, one shared screen
These are pass-and-play: two people, one device, take turns. I have a soft spot for the mathematically deep ones that look like nothing.
Hex is the connection game where you race to link your two sides of a rhombus board — famously, it can never end in a draw, and the first player provably has a winning strategy nobody can actually memorise, which is a lovely thing to hand two people who think tic-tac-toe is the ceiling. Nim is the take-away game that's secretly binary arithmetic; once someone works out the trick they become unbeatable, and watching them try not to reveal that they've worked it out is half the fun. Sprouts is the pencil-and-paper topology game — draw dots, connect them, don't cross the lines — that I wrote a whole case study about, because the empty search results for it turned out to be a signal rather than a dead end. And Four in a Row is the drop-the-disc classic everyone already knows the rules to.
Make-your-own review games
The other camp is for teachers (or anyone running a quiz night). You bring the questions; the game supplies the fun of answering them.
Whack-a-Mole turns a question set into a reflex game — right answers get whacked, and a class that groaned at a worksheet will fight over the buzzer for the same content. Plinko adds the chaos of a bouncing disc and a points board, so the review has a lottery element that keeps everyone watching. And the emoji guessing game maker lets you build "guess the phrase from the emojis" puzzles — 🎬🍿 for movie night — which works for a lesson starter or a party alike.
Companion tools for the games you already play
A few aren't games themselves but sit next to the ones you play elsewhere. The D&D travel time calculator works out how long a party's overland journey takes; the Minecraft potion chart and villager trading chart are the brewing and trading references you'd otherwise have open in another tab; and the Stardew keg vs dehydrator calculator settles the eternal "which processes my crop for more gold" question. They live in the gaming tools hub alongside the rest.
Where to find them
The two-player games live in the browser games hub; the review games double as classroom tools, because a game that makes revision feel like play is exactly what a Friday afternoon needs. All free, all in-browser, nothing to install. Grab a friend or a class and go.