Roku remote functions work flawlessly, but what is the function of the top left "Computer" button in the grid. I thought perhaps cast the screen to Roku? It seems to have no effect when clicked. Thank you!

The vague description of this extension does it a huge injustice. I will note that it does require the user to provide the IP address of one or more Roku device(s) they wish to connect to. That said, after entering that one piece of information, the add-on worked flawlessly even after reboot. It has a very clean yet feature rich UI that enables one to not only cast video to a Roku device but also includes an interactive virtual remote that overlays your browser window and let's you control your Roku device with nearly the same level of precision and feature parity as that of a proprietary Roku-branded remote (i.e. the original remote that shipped with your TV). Even if the Roku device you're controlling isn't in your direct line-of-sight (i.e. it's in another room) not to fear, this add-on includes a real-time mini-rendering of what the Roku device is displaying so you can navigate dynamic menus and respond to any unexpected popups or login events that would otherwise create endless headaches. Well done.