Is there a keyboard shortcut in Mozilla Firefox that allows the user to switch back and forth between 2 tabs in a single window? I'm looking for a command exactly analogous to Alt+Tab for Windows programs and folders. That is, I want a shortcut that allows me to go back and forth between 2 tabs, the last one that had the focus and the one that currently has the focus. I don't want a keyboard shortcut that lets the user move from one tab to another adjacent tab.
If not, is there a Firefox add-in that adds this function to Firefox.