Internet Explorer
Mouse Gestures:-
The simple to use and highly customizable add-on allows you to set various commands from most common function of the browser such as ‘back’ ‘new tab’ and so on. It also comes with an editor to make your own gestures.
Quero Toolbar:-
This toolbar for internet explorer not only allow you to search and visit websites but also act as a pop up blocker it replaces the address bar and adds various features including a compact button layout and the option to hide flash content.
ieSpell:-
This plugin scans spelling errors as you type. It works across forms, blogs, social networking sites, allows you to add words to its database in custom dictionaries and even allows you to check for definitions.