Default make two devices' screens work as one

Hi there!
I've been asked to do some R&D on making two Android tablets' screens work as one, like some kind of extended desktop. I've been looking for apps that do the job, but I've only seen this feature between a computer and a tablet. The closest thing I've found is the Pinch interface for iOS, but there seems to be nothing similar on Android. Here's an example:

youtube v=jRGLkj-PsCc

(can't post links yet, so there's the video ID from youtube)

I've been told that programming a daemon that listens to the touch events and sends them from one tablet to another could do the trick, but I'd like to explore other options first.

Any thoughts on this subject?

Thanks in advance.