kontrol 49 and FREE ASSIGN

I have the KONTROL49 now for one year. And I use it often and it's great. But it should be compatible with something called FREE ASSIGN. I got my KONTROL49 second hand and without the driver cd. So I cannot find anything called FREE ASSIGN...

Is it a VST-i, is it something else? I love to hear from other KONTROL49 owners what that FREE ASSIGN is/was...

Thanks