Diver++ is a little system utility, MDI program, that allow you do some usable things, you need in working/testing process.

What can it do?

+ send messages to choosen window.
+ search window by mouse moving, or
+ by handle.
+ change state of window:
+ enable/disable, show/hide/restore/maximize/etc...
+ change position, z-order, parent of window.
+ cnange style, extended style of window.
+ show windows hierarchy.
+ change window font.