ReplayChess

ReplayChess turns chess history into something you play. Pick a legend (Morphy, Fischer, Kasparov, Carlsen and 50+ more), jump into one of their famous games at its critical position, and try to find the moves they found. Play it out against a friend via a private link, a matched opponent, or Stockfish running in your browser.

After the game you get a move-by-move comparison: your match rate against the original and the exact move where you diverged. There is also an openings encyclopedia of 3,600+ ECO-coded positions to play from, rating-based matchmaking, tournaments, and it installs as a PWA. Free to play, no ads; Player plan $4.99/month. Open source under MIT.