“Quit FKEY” forces currently running application, even Finder, to quit immediately. This is useful when the application refuses to quit or you don’t know how to terminate an application. This FKEY works like a panic button. It may be installed in System file or specific application by copying with ResEdit.
It may leave temporary files behind. It will not update any changes in documents. Try not to use when the disk is running. This may lead to damage to your disk.
It is only 2-byte-long(A9 F4), yet useful, FKEY. Of course it’s free. Enjoy.