I looked at Android 4.0 and see no multi-window feature so if some company extended the OS then they have to only allow apps that work or the owners may complain about apps that don't work right.
Are you new to Android?
I recently bought the Samsung Note Tablet 10.1 and am very impressed with the performance. what I don't like is that it would seem only SAMSUNG can tell us what we can and cannot use in dual-window mode! I want to be able to add what ever application I choose and open 2 at the same time on each side of the screen. I have searched all over and found nothing. Does anyone know any way to do this? If not, Samsung needs to work on this for sure!