How could others, on a local network, access my NodeJS app while it's running on my machine?

Question

I have a pretty straight-forward question. I made a web game with NodeJS, and I can successfully play it by myself with multiple browser windows open side-by-side; however,

Answer 1

var http = require('http');
http.createServer(function (req, res) {
}).listen(80, '127.0.0.1');
console.log('Server running at http://127.0.0.1:80/');