In one embodiment, a method includes displaying a first content item on a screen of a computing device, the first content item occupying the entire screen and comprising an icon representing a second content item; and in response to a first user input, displaying a first animation sequence depicting the icon opening up to reveal the second content item, the second content item eventually replacing the first content item and occupying the entire screen. Then, in response to a second user input, the method further includes displaying a second animation sequence depicting the second content item closing down and returning to the icon included in the first content item, the second content item eventually disappearing from the screen.