Man, your app is working fine...
Just download xampp or wamp, install and copy it to the localhost server folder
Copy the files in your Ext designer folder to one of those, and just run localhost/xds_index.html in your browser... the images are not loading because the link is broken, you need to copy them in your "server" and rename the url's... If you want to see the project just like in the tutorial (in the Ext designer preview), I have no idea how to do it... I have always used wamp for preview