Clear Cookies and Storage Button v1.1resigned1
This Add-On adds a button to Firefox's toolbar. You can remove cookies, supercookies and web application data with a simple click - enhancing your privacy online. What exactly you want to delete can be configured in the add-on's settings.
The default is to delete Cookies, indexedDB and localStorage data backends.
You can achieve similar functionality in Firefox Settings (about:preferences#privacy) purging a number of data stores upon closing Firefox. This button enables you to do the same without closing the browser.
Note that it does not (that's good) delete data stored by other Firefox Add-Ons (this data is stored and browsable in about:config). If it would, the Add-On would, among other things, delete it's own settings...
This Add-On is a slightly modified version of Mozilla's own "forget-it" example code, which wasn't available on https://addons.mozilla.org/ until now.
Brought to you by the nice people at video search engine Lumerias, who care about your privacy.