Of course lichess.org was mentioned, but it got me excited to build something simple with not too much scope creep. So that's what I tried to build: simple, without signup and supporting slow (make a move every week) or fast (sse based) games.
Built with PocketBase[2] (customized to f.e. support web push), chess.js[3] and Claude it rekindled my interest in chess and I started playing it offline again and shared some game invites with friends.
Hope some of you like it -> https://chessinvite.com