Alt+` does this, right next to Alt+Tab, within a single application. So if you wanted to pick a particular window, and you have five apps with three windows each open, instead of pressing Alt+Tab ceil~14 times, you press Alt+Tab until you have the app you want (possibly zero times) then Alt+`, potentially saving 12 or more keypresses.
Re:Ubuntu 14.04 LTS
by andrewaylett on Friday April 18, 2014 @11:48AM
(#7609640)
Or, sometimes even better, press Alt-Tab once, then hold Alt and use your mouse to select which app then which window you want.
In case you wanted more proof of this I think both of these are wrong and it should be by window not application. Thankfully MATE does this and is coincidentally available now in Ubuntu 14.04.