If you test the DEMO of Simplify Extend, you will find that OK without any problem.
We found that you are using caching plugin. Your Responsive Style sheet is not loading. Please activate the Responsive Layout and clear/purge the cache from the Plugin and check again. If you still see the site without activating Responsiveness you can provide us one temporary Admin ID and Password HERE so that we can check your Dashboard. We can make you sure that This is not a Theme Issue.
