When you click and hold the icon of a running application in the OS X dock you get a list of current app windows that you can pick from. The list of windows appears after some time interval. Is there a way to reduce this interval?
If your Mac has a trackpad, you can click with two fingers to bring up that menu without delay. If it has a Magic Mouse, you can click on the right side of the mouse. If it has a standard PC mouse, you can right click, and whatever hardware you have, you can also hold Control while clicking to do the same thing. This also brings up other context menus in all sorts of places in the system! Hope this helps.