Systems, methods and apparatus for using a magnetic controller to control device. In one aspect, a system includes a magnetic controller external to a device, the magnetic controller including: a magnetic device for altering a surrounding magnetic field of a device; one or more input actuators, each operatively coupled to the magnetic device and that when actuated cause the magnetic device alter the surrounding magnetic field according to a predefined change associated with the input actuator; and a model executable by the device and that models as device inputs the differences in the surrounding magnetic field of the device caused by the actuation of the one or more input actuators.