‘Disable All Extensions Plus’ is an extension for Google Chrome that allows you to quickly enable/disable all extension and apps with a single click.
On installing, the extension adds a new button to the toolbar, from where you can manage all your installed add-ons in a convenient drop-down list as seen in the image on the right.
The first option in the menu disables everything at once, and clicking on it again enables them back.
If you want to enable/disable individual extensions, simply click on it.
You can also uninstall any unwanted extension or app by right-clicking on it.
Download: Disable All Extensions Plus from Chrome Web Store.
Another nice extension to access and organize Chrome apps is AppJump.