This add-on works well, in Firefox on Android. When configuring the app for individual web sites, the fully qualified domain name for the site should be specified with the site's complete hostname - e.g www.google.com as instead of google.com. For any pages open when the add-on is installed, the add-in's functionality may become available then, once the page has been reloaded. Of course, it would be available for new pages and tabs too. Works well as a workaround for Google having apparently removed the "Open search results in new tab" option from Google "Search Settings."