This extension can simplify the rule to just specify the URI and Content type and can enable/disable each rule separately.
What's more, it can customize the web pages by user scripts which is similar to Grease Monkey.
Anti-Aliasing Tuner for Direct2D/DirectWrite Text Rendering
Adds a commandline argument to load Firefox faster at Windows startup
An extension which supports one-click downloads of illustrations from Pixiv. It's able to choose automatically appropriate file names.
It also supports full screen view of large illustrations on medium-sized screens.
Extension to clean and vacuum your firefox places database.
Select text and it's automatically copied to the clipboard. Also pastes on middle click.
Add "Go Parent Folder" menu to context menu in The Library list view and Search result in Bookmarks Sidebar.
Collections are groups of related add-ons that anyone can create and share.Explore Collections