The evidence was found on the side of Gameloft's meeting room at E3, which shows Harry and Voldemort (at least Daniel Radcliffe and Ralph Fiennes) in profile, sizing each other up for their final encounter.
And perhaps it's not too far-fetched in the context of Gameloft and EA Mobile's arch-rivalry to say that the French publisher has pulled off a Massivius Surprisium spell, given that EA has released all Harry Potter video games to-date, having secured the licence on a deal rumoured at around $500 million before the first film was made.

Of course, with the deal not yet formally announced, we have no idea in what form the mobile game will arise only that its official title will be (deep breath) Harry Potter and the Deathly Hallows Part 2: The Mobile Game.
Presumably, it will be released alongside the film around July 15.