Edit the file dynamic-cache-test.php in the plugins directory and you’ll see all the code is commented out. I’ve just updated that file so you might want to grab the development version again in about 20 minutes.
It’s using a constant for the template tag now so users will have to come up with their own secret one.
Also, the plugin is always active once the code is uncommented and that constant defined. I didn’t bother with a nice UI to toggle it.