Source: Extensity – Chrome Web Store
There are times when you want to quickly disable or enable an extension, without going through the process of opening the extensions tab. Extensity adds an icon to your toolbar to quickly enable or disable an extension.
After clicking on the icon, all of your extensions are shown. Disabled extensions are grayed out, while enabled extensions are not. Clicking on an extension toggles its enablement (how about that for a made up word!).