A computer system or electronic device displays, at a first time, a first user interface that includes a placement location and is configured to spatially accommodate a respective user interface object of a plurality of user interface objects, including first and second user interface objects. At the first time, the first user interface object is displayed at the placement location. At a second time, the first user interface is displayed with the second user interface object at the placement location. The second user interface object is automatically selected for display based on a current context of the device at the second time. In response to detecting a gesture of a first type directed to the placement location, the second user interface object is replaced with a different user interface object from the plurality of user interface objects associated with the placement location.