1. Apparatus for communication between a user and a device, comprising: a hardware sensor in or on the device that senses attention of the user specifically toward the device; and a processor that processes a signal from the hardware sensor and outputs to the device a measure or index of the user's attention toward the device; and wherein operation of the device is modulated on the basis of the measure or index of the user's attention toward the device; wherein the operation that is modulated is initiated by the device and provides a notification and/or information and/or communication to the user based on the user's attention toward the device.