Addoncrop - Extends the functionality of your web browser
Extensity - Quickly enable/disable Google Chrome extensions.
Chrome Extension Downloader - Chrome Extension Downloader is the name of a website dedicated for downloading and Chrome extensions.
Extensions switcher - Menu for quick extensions control
Opera Add-ons - Get extensions and themes for the http://alternativeto.net/software/opera browser.
Extensions Manager (aka Switcher) - Light popup manager to enable, disable, uninstall extensions, applications quickly and easy.