This app is designed to make it so that you can cast hulu videos to chromecast. Simply install the extension and open a video as normal on hulu. It should open into a video that will take up the full tab, thus making it cast to chromecast correctly.
You may need to resize the tab to get rid of black bars, but that's easier than the hoops you used to need to jump hoop.
Thumbnails should have a green background behind the link text when this is active.