My implementation of the board game Tigris & Euphrates using boardgame.io and React. You can play Tigris & Euphrates as well as some other games at https://lhog.herokuapp.com/.
This implementation mostly uses drag and drop. There is no log of moves (in order to obscure points) so playing asynchronously might be somewhat confusing. I haven't implemented any rules help/tooltips, so I'd recommend familiarizing yourself with the rules before playing.
Run npm install to install the necessary packages. Run the server using npm run server and the client using npm start. This will instantiate two game boards in a single window for easy testing.
Check out Lewis' House of Games for a deployment which can host many boardgame.io games.
To publish the package to npm, run npm run publish:npm to compile files for publication, followed by npm publish.