Adds a “Open a new tab on the left” action button and a “Open Link In New Tab on the Left” context menu item for hyperlinks.
The “Open a new tab on the left” button opens a new tab, but puts it all the way on the left of the tab bar. This complements the standard new-tab button, which puts things on the right.
Similarly, the “Open Link In New Tab on the Left” option opens a link in a new tab on the far left.
This add-on supports custom about:newtab urls.