The apparatus 100 comprises means 101 for detecting a weight applied to the apparatus 100 and means 102 for sliding the apparatus along another surface 103 separate of the apparatus 100. A system is also provided which comprises the apparatus 100 with one or more sensors (501, 502, fig 5) which are remote of the apparatus for sensing at least one of movement, acceleration or orientation of the apparatus. Furthermore a computer program is provided for receiving, at a remote device (401, fig 4), a signal transmitted from the apparatus 100 and generating an output dependent upon the received signal.
