Three men's morris is one of the oldest alignment games in the world: each player has just three pieces on a nine-point board, and the first to line them up wins. The Romans knew it as terni lapilli — "three pebbles" — and left its boards scratched into pavements, steps, and roof tiles across the empire. In Tamil Nadu the same family of games is played on a 3×3 square as kattam vilayattu.
align3 offers both boards, and they are genuinely different games rather than skins. The Roman circle wins along its four spokes or any three consecutive points on the rim. The Tamil square wins only on the eight straight lines of the grid — rows, columns, and diagonals — so bent triples along the edge don't count.
Two players share one screen — a phone passed between hands or a laptop set between you; there is no computer opponent, no account, and nothing to install. Take turns placing your three stones on empty points. Once all six stones are down, the game shifts to movement: slide a stone along a line to an empty neighbouring point. Legal moves light up as you go, so the rules teach themselves in a round. First player to align three stones wins — then play again.
Also from Aakkagam Games: Ostomachion, Archimedes' fourteen-piece square puzzle, and Senet, the ancient Egyptian race game.