If you've accumulated a large collection of tabs over a few days, save energy by randomly selecting one to review. Pressing the toolbar icon will change to a random browser tab; Ctrl-Shift-Y does the same from the keyboard. (Shift-clicking on the toolbar icon will delete an existing tab at random--save more energy by skipping review!)
Added feature to allow random selection of an audible tab (a tab that is playing audio). Alt-click on the extension icon or Ctrl-Shift-M on the keybord will select a random audible tab.
