Add Github android app to real-world uses

Author: marijnh

index.html

@@ -120,6 +120,7 @@ <h2>Real-world uses:</h2>
       <li><a href="http://brackets.io">Adobe Brackets</a> (code editor)</li>
       <li><a href="http://www.mergely.com/">Mergely</a> (interactive diffing)</li>
       <li><a href="https://script.google.com/">Google Apps Script</a></li>
+      <li><a href="https://github.com/github/android">GitHub's Android app</a></li>
       <li><a href="http://eloquentjavascript.net/chapter1.html">Eloquent JavaScript</a> (book)</li>
       <li><a href="http://media.chikuyonok.ru/codemirror2/">Zen Coding</a> (fast XML editing)</li>
       <li><a href="http://paperjs.org/">Paper.js</a> (graphics scripting)</li>