This is pretty easy to do. You can create a Utility Application from the template in Xcode, which already has the view-flipping implemented. Take the boilerplate OpenGL ES view code generated by the OpenGL ES Application template and replace the main (or flipside) view s code with the OpenGL ES view s. That should be enough to make a functional application to start with.
For an example of this in action, you can download the source code to my iPhone application Molecules, which has an OpenGL ES view on its main side and a navigation view controller on its flipside. It s a little more complex than the templates I describe above, but it is a fully functional application that does what you re looking for.