Here a cover that reacts on gravity, a funny gadget, haven't seen this before applied on a cover.
When you move your iPad, the figures on the cover move fast/slow over the screen.
It's the new PROJECT, Richard Branson's newest mag specially ctreated for the iPad: "The 2011 summer Movie Blowout"

"A magazine built entirely with the iPad in mind. PROJECT is a magazine about entertainment, design, technology and entrepreneurs. Available at Apple’s app store."

Editor in Chief Anthony Noguera
Deputy editor Chris Bell
Art director Che Storey