I brought this expecting this to work with my existing hive heating and hot water control, tried adding to my existing plan, it won't work unless you sign up for a additional fees with British Gas. In my opinion buy it from the gas board, they will give you a free contact for a year.
Firstly I found you need a £3.00 / month subscription to use this, then after reading other people's very poor reviews of the item I cancelled the order
Was not a stand alone product that worked with the Hive App. but requires a monthly subscription for Hive to monitor the product.
I should have done better research as to its operation.