Encanto Go is a client-only correspondence Go app. Instead of using accounts, servers, or a shared database, each move updates the URL with the full game state. Opponents can send the latest link back and forth to continue the game from any browser.
The app is built for simple asynchronous play, with board-size selection, local browser color assignment, move validation, and installable PWA support.
I've never actually finished a game. I assume it works, but just in case I wouldn't use this app for high stakes competition Go 🙂