If you installed from the Add-ons site, you should find those add-ons listed here: menu > Tools > Add-ons If you tap an individual add-on, it might have options. Otherwise, you could check whether the add-on added itself to the menu somewhere. If it doesn't show up anywhere in the menus, maybe it has some other UI? For example, Ghostery displays a ghost icon over the page. If you can't find it anywhere, do you want to mention which add-on(s) you're trying to use?