Add a 'Dislike' feature on Facebook. Facebook Dislike implement a "Dislike" button on Facebook.
The "Dislike" button will be placed right next to the "Like" button, so you cant miss it. It also has an option to disable/enable auto-post comment

Requirements:
* Firefox
* Firefox for Mobile
* Thunderbird
* Facebook account

The license of this software is Freeware, you can free download and free use this browser plug-ins software.