Abstract: A portable device comprising a modular movement is disclosed. The modular movement has a body housing a plurality of layers that include a top layer of glass, and a movement subassembly for displaying information, including time, wherein the modular movement includes all parts necessary for power and operation, including the displaying of the information, such that the modular movement is fully functional standalone. The portable device further includes a case, which includes a receptacle for removably receiving the modular movement without need for a tool, such that the modular movement is user-interchangeable with another case of another portable device.