An apparatus having a ring-shaped housing configured to be wrapped round a finger of a user, the ring-shaped housing having an opening or a joint at a first point round the finger and a first contiguous section that is at a location opposite to the first point across a central axis of the ring-shaped housing; an antenna configured in the ring-shaped housing in the contiguous section; an inertial measurement unit configured to measure motions of the finger; a light-emitting diode (LED) indicator configured on an outer portion of the ring-shaped housing; a charging pad configured to charge a battery configured in the ring-shaped housing; and/or a touch pad configured to receive touch input from a finger of the user.