I've read it's not possible for iOS, but it is possible to control more than 1 ball at a time for android. But nothing about using 2 or more balls with 2 or more devices in the same area.
We'd love to use 3-5 of them in the same area with 3-5 android devices controlling 1 ball apiece.
I take it, if you had 3 different versions of your app, one on each device, will they conflict with one another? I doubt you could see a character on each of the other balls you aren't controlling. But if they'd still work in the same space we might still go for it.