google.user.js

// ==UserScript==
// @name         New Userscript
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.google.co.in/
// @require      https://fb.me/react-0.13.0.js
// @grant        none
// ==/UserScript==



var App = React.createClass({
    render: function(){
        return(React.createElement("div", null, "It works!"));
    }
});
React.render(React.createElement(App), document.body);