In some embodiments, a computer-implemented method performed at a portable electronic device with a touch screen display includes simultaneously displaying a character input area operable to display text character input and emoji character input selected by a user, a keyboard display area, and a plurality of emoji category icons. In response to detecting a gesture on a respective emoji category icon, the method also includes simultaneously displaying: a first subset of emoji character keys for the respective emoji category in the keyboard display area and a plurality of subset-sequence-indicia icons for the respective emoji category. The method also includes detecting a gesture in the keyboard display area and, in response: replacing display of the first subset of emoji character keys with display of a second subset of emoji character keys for the respective emoji category, and updating the information provided by the subset-sequence-indicia icons.