The upcoming Angry Birds Movie will feature a secret clip only viewable on cinemagoers' phones, Rovio has revealed.
The technology, which Rovio calls 'Movie Magic', lets anyone who sticks around for the end credits during the film's opening weekend watch an exclusive clip inside the series' latest game Angry Birds Action, as well as unlock access to a brand new area in the game.
The tech works by playing an inaudible "digital watermark" during the credits sequence that activates the bonus content to anybody running the game on their phone.
"By going to see The Angry Birds Movie in the cinema during the opening weekend and sticking around for the credits, audience members with the game open on their device get treated to more Movie Magic - a whole new area of the game to explore and an additional exclusive movie clip that can't be seen anywhere else but inside Angry Birds Action!" Rovio said. "Movie Magic works in the game by detecting an inaudible digital watermark that plays only behind the end credits."
The Angry Birds Movies hits cinemas on May 13, with the pinball-inspired Angry Birds Action available to download on mobile now.