I am looking for something that will allow me to set on/off timers and temperature on a conventional cylinder with thermostat and 3KW heating element.

I already have a timer on the switchboard but space is tight, so would like to replace this with a device that is in the hot-water cupboard and includes temperature settings and record actual on/off timings.  Ideally this unit should have a phone/tablet app and Bluetooth etc.  I am expecting that a sparky install is needed.  I also have an under-bench cylinder in the kitchen and would like to be able to control this too.

The overall objective to to identify how many KWH is consumed by hot-water heating and what effect adjusting the temperature has.  This is a household of 4 adults and monthly power consumption is around 1100 KWH.

I don’t use any form of home automation tech.