In this app, the mobile analytics and advertising company Medialets is serving up an ad for the new album, Contra, by the band Vampire Weekend. At first, the ad just peeks out at the bottom of the NPR app, but if you click to expand it, it quickly takes up the entire device. So why would you want to do this? Because it’s a video for Vampire Weekend’s new song “Cousins” — and thanks to some of the iPhone’s unique features, you can actually interact with the ad, shaking your iPhone to change how the video looks.
