Web Extension List
These are all the button that I have ported to Firefox 57+ so far.
Bookmark Toolbar Menu
Show the contents of the Bookmarks Toolbar in a drop down menu.
This compresses the bookmark menu into one button that you can put on any toolbar you want to.
Go to the very bottom of the current page.
Clears the browser cache and other selected storage.
Close all the the currently open tabs.
Close Other Tabs
Close all the currently open tabs except the selected one.
Close the currently open tab, or if there are no tabs the open window.
Close Tabs to the right
Close all tabs to the right of the current tab.
Opens a color picker dialog window, to chose and work with colors.
Makes a copy of the current tab
Scroll current tab one page down.
Scroll current tab one page up.
Open the Print Preview to view a page before printing it.
Paper costs money (and trees) so it is worth checking what the page looks like before you print it. Though it has always amazed me just how much the button gets downloaded.
Recently Closed Tabs
Open a list of the recently closed tabs. You can select tabs to restore from the list.
Reload Skip Cache
Reload page without using content stored in the browser cache to make sure you get any updates.
Reload all open tabs.
A button with a popup for searching your bookmarks.
Go back to the very first page that was opened in the current tab.
Stop all tabs from loading when you have mass opened tabs and found the one you really wanted.
Scroll the page to the very top.
A list of the top sites that you visit.
Undo Close Tab
Reopen the last closed tab. Really nice when a tab is closed by mistake, or you decided you did not really want to close it moments too late.