According to one embodiment, a magnetic sensor attached to a mobile device detects a magnetic field generated from a magnet attached to an object. A magnetic sensor data processing module generates magnetic sensor data based on the magnetic field, where the magnetic sensor data represents a current position of the magnet of the object. An action processing module processes the magnetic sensor data to determine a movement of the object with respect to the mobile device, while the mobile device remains in a relatively steady location and identifies a predetermined action based on the movement of the object. The predetermined action is then performed within the mobile device.