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 ea

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.