Please consider adding an UI element for adding/removing the site from the whitelist without having to manually edit the string in the settings. This UI should appear in the popup menu when the extension icon is clicked. This extension would be much more usable with this.
UPDATE: This is great! As I mentioned on Github, I missed this because I'm not used to paying close attention to the icons in the address bar often since I'm using Tridactyl. I've updated my rating accordingly.