Overlayer
Window management utility for Windows; turn programs into overlays.
... into an overlay.
For example, your games, or perhaps some documentation you were reading: allowing it to persistently stay on top of another window, without blocking out the content thanks to transparency, while also not having to worry about accidentally clicking on it, thanks to click-through ghost windows, but being able to interact with it when you *choose* to -- what you're left with, is a window with all of the attributes that make a dedicated overlay, and overlay, but present in an ordinary window