To deal with some of the changes in Mac OS X, I ran apps and system extensions that restored some behaviors from classic Mac OS. Over the years, I weaned myself off most of these, but a few stuck. In particular, I found I did not want to live without the window layering policy from classic Mac OS.
In classic, when you click on a window that belongs to an application that’s not currently active, all the windows that belong to that application come to the front. In Mac OS X (and macOS), only the window that you clicked comes to the front.
Front and Center is a trivial app—so trivial that I was afraid it would be rejected for its limited functionality. But when running, it is used literally hundreds of times a day. And I obviously found it so essential that I was willing to help bring it into existence myself.
Call me an old dog who can’t learn new tricks but this might be the fastest I’ve ever spent three dollars.