In one embodiment, a method includes detecting a touch event on a back-mounted touchpad of a computing device during display of a current user interface of an application executing on the computing device. The application includes a navigation hierarchy with a home user-interface layer, multiple sub user-interface layers, and multiple user-interface branches. The method includes determining a particular sub user-interface layer and user-interface branch that the current user interface corresponds to and determining a type of the touch event. When the type of the touch event is an upward touch event and there is a next sub user-interface layer in the particular user-interface branch of the current user interface, the method navigates to the next user-interface layer in the particular user-interface branch of the current user interface.