One-handed operation of a wearable computing device is provided. An indicator is displayed on a graphical user interface of a wearable computing device. A directional displacement of an interface device is determined, wherein the interface device is removably connected to a finger of a user of the wearable computing device. An association is made between the indicator and a graphical user interface object based, at least in part, on the directional displacement of the interface device. A graphical user interface is modified to visually indicate the association between the indicator and a graphical user interface object. In response to determining that a force exerted by a surface in contact with the interface device exceeds a threshold, a graphical user interface object is activated.