1. A method comprising: displaying in an interface of a mobile device a listing of content items on a display of the mobile device, the listing of content items comprising at least one boundary between groups of the content items; receiving a user input to scroll the listing of content items from a first content item on one side of a boundary to a second content item on another side of the boundary; and responsive to the user input, scrolling the displayed listing at a first velocity from the first content item to the boundary, scrolling the displayed listing at a second velocity slower than the first velocity when the boundary is reached, and scrolling the displayed listing at the first velocity from the boundary to the second content item.