I am not familiar with that particular extension. The reviews seems to indicate it doesn't work for everyone. Here is how you can turn on Firefox's built-in "click-to-play" feature for Flash. This will delay Flash from starting on a page until you approve it. To set Flash to "Ask to Activate", open the Add-ons page using either: * Ctrl+Shift+a * orange Firefox button (or Tools menu) > Add-ons In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate". When you visit a site that wants to use the Flash, you should see a notification icon in the address bar and one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page. Once you approve Flash on a site, all movies on the page will load. If you want one-by-one control, there is a different extension designed to work with Firefox's click-to-play feature: https://addons.mozilla.org/firefox/addon/click-to-play-per-element/ Hopefully that helps?