Setting Up React

First install the packages:

npm install --save react react-dom reactify

Then add to your browser transform in server/index.js:

   routes.get('/app-bundle.js',
-    browserify('./client/app.js'))
+    browserify('./client/app.js', {
+      transform: [ require('reactify') ]
+    }))

And that's it! Now you can start using react in client/app.js. Here's a starting point (replace the code in client/app.js with the following):

// client/app.js
var React = require('react');
var ReactDOM = require('react-dom');

ReactDOM.render(
  <h1>Hello, world!</h1>, // JSX
  document.getElementById('app')
);