Quadraxas, I just tried your tool on my new Windows7 system.
Wow, great, it works now for me, and it looks way better than that tool that I used before, because it doesn't show the ugly window frame.
You can see here some video tutorials that I made with the osdHotkey:
youtube video tutorials and others of Pappenheimerr

Unfortanately your tool doesn't show the mouse buttons and mouse wheel.
osdHotkey displays: mouse_right, mouse_left, mouse_middle, mouse_wheel_up and mouse_wheel_down.
It is important for tutorials with Blender for instance.

Maybe, the displayed key shouldn't disappear immidiately, better it fades away.

When you add an option to add an own picture with alpha channel, and the option to choose ones own font, it is almost perfect.
Then everyone can create the exact outfit needed for his specific tutorial.

Thank you for your kind contribution.