A convertible supporting device includes a base, rotatable portion, and a rotation mechanism. The base is for a supporting device having a bottom surface. When exposed, the bottom surface of the supporting device is for contact with another surface to provide support for a user of the supporting device. The rotatable portion is coupled to the base and is rotatable relative to the base. The rotatable portion includes a work plate including an upper surface and a lower surface. The work plate defines through holes across a plate thickness between the upper surface and the lower surface. The rotatable portion also includes one or more elements, a portion of which is exposed beyond the lower surface of the work plate. The rotation mechanism connects the base and the rotatable portion.
