This simple addon opens links in a new active tab with Shift+LeftClick (left mouse button click), not in a new window
Mainly for users, who used this shotcut in other browsers (e.g. Opera 12).
You can select your own mouse + mod key combination.

Save all tabs in a window to check it later

Lets you open a new tab at any position. Using different configurable ways (keyboard shortcut, toolbar button, context menus of tabs, …) you can open tabs anywhere you like.

A 'View MathML Source' context menu item

This app closes your p0rn tabs all at once!

control contents permissions per tab

Manage tabs as a groups (window).

Integrate Firefox with Windows Timeline, and send links to your Android or Windows phone quickly.

Invert page colors.

Make a page easy to read

This addon allows you to separate app (pinned) tabs from normal tabs.

Discover a Deezer Track every time you open a new tab.

Invert light-themed web pages into dark to reduce eyestrain

ReDraw text Vertical direction.
change font , color , line space
Drag view mode (like pdf)
縦書きの描画にチャレンジするがんばりやさん。小説や青空文庫を読むのに楽しんでください。
フォントやカラーの変更、ドラッグで掴んでスクロールもできます。

Copy Tab URL with custom format. Right click on Tab for use it.

Aggregate new tabs to a window which has most many tabs and largest size.

Adds the URL of the tab to the windows title:
* optional delimiter (e.g. ' - ')
* optional protocol (e.g. 'http://')
* hostname (e.g. 'foo.org')
* optional path (e.g. '/foo.php')

This is for instance useful for keepass/keepassX.

Suspend / unsuspend a tab, with minimal privacy concerns by design

Open every bookmark in a folder, including those inside subfolders.

Adds a context item to the tab menu that close all tabs to the left of the selected one. The menu item is translated for English, French, Italian and Polish.

Will automatically close tabs"websites"(POPUPS) you add to Blacklist.

For people like me who have way too many tabs open and are too lazy to go through and delete them, Too Many Tabs will help manage your tabs in bulk based on URL.

Disguises the title and favicon of a tab

Allows to save ten URLS as bookmarks in a popup

Find Emails and Generate Leads

Discover and download Lottie files used on a page

Find and replace text in the url across all of your tabs. Easily search for and replace specific strings such as dates, tokens, queries, and more.

This app is designed when you have many tabs open and need to replace a particular string in the url

Open a new tab next to the current one using a hotkey

A basic extension which enables the user to save current tabs and windows in different profiles which can then be loaded for convenience!

Navigate to next page if page URL is ending with a Id as parameter. Check right arrow in address bar.