Why is it essential?
I would think if you use Traktor with your 3000, that you would opt for Traktor DJ for the iPad. A very nice DJ app and perfectly suited for doing library work while en route.
The other software I’d certainly check out is DJ Player. Not a real life look alike, but a true DJ iPad app designed for that platform from scratch. Fully utilizing the features/capabilities of the iPad platform. Very very nice.
They also allow you to use your iphone or wifi ipod to use your headphones wirelessly, neat trick!
Although I have the iDJ Pro as my backup and small gig controller and it comes with default mappings for DJay, I am not particularly fond of it. I am anxiously awaiting the DJ Player mappings for it.
Greetinx,
C.