WP One-Click Installer FireFox Extension

Download Link: One-Click Installer FireFox Extension.
Description: This extension can be used to install plugins or themes on your WordPress blog with a single click. It adds a new entry to the popup context menu for links to .zip files, clicking it installs the plugin or theme file on the Wordpress blog you have configured in the addons settings (the type – plugin/theme – is determined automatically).
Note: You need the following plugin installed on WP for this addon to work: Click Plugin Updater v. 2.2.

Wordpress.com Sidebar FireFox Extension

Download Link: Wordpress.com Sidebar FireFox Extension.
Description: Get quick access to your wordpress.com account from Firefoxs sidebar. Easy to install and use.
Note: This extension will not work on self hosted blogs, pity that.
Install Video: http://gamespotting.net/wordpress.htm.

Deepest Sender – Blogging Client FireFox Extension

Download Link: Deepest Sender – Blogging Client FireFox Extension.
Description: Deepest Sender is a full blogging client for Firefox. This means that instead of having to go to the Update page on WordPress, or loading up a separate client program, all you have to do is hit Ctrl+\, or click the button in your toolbar, and you can start posting. A truelly amazing extension.
Note: It will run on the following Browsers Firefox, SeaMonkey, and XULRunner.

DashBlog FireFox Extension

Download Link: DashBlog FireFox Extension.
Description: DashBlog is an extension that allows you to take videos on any webpage and then quickly post them to your Wordpress blog.
Note: When it says “take“, I am sure you will ask the owners permission first.

Clipmarks FireFox Extension

Download Link: Clipmarks Firefox Extensions.
Description: Clipmarks lets you capture exactly what you want others to see (text, images or video). Your clips are saved on clipmarks.com. You can then post anything you clip directly to your Wordpress blog.
Note: As well as Wordpress it also supports Blogger and Typepad.

WordPress Helper FireFox Extension

Download Link: WordPress Helper FireFox Extension.
Description: This extension gives you useful help and tools when you work with Wordpress. You will have quick and simple access to the WP Codex. It’s also possible to search after strings of text that is currently marked. Furthermore it’s possible to easily switch to WordPresss backend of the current site. More than that, a small Icon indicates wether the currently displayed website makes use of WordPress. I have just installed this plugin, I hope it is as good as I hope.

Screen grab to WordPress! FireFox Extension

Download Link: Screen grab to WordPress! FireFox Extension.

Description: This addon will grab a screen capture of any size, andallow you to directly upload it to Wordpress (2.5+).