I use E.On for both my gas & electricity. Last year I was contacted and asked if I would like to have Smart meters installed. Being a bit of a geek, at said yes. Free of charge of course.
Installation for both meters took less 2 hours. Included in 'the package' is a Smart meter monitor.
The gas meter is linked via Bluetooth to the electricity meter. It is the electricity meter that has the GSM mobile connection to 'the outside world'.
The Smart meter monitor is also linked to the electricity meter by Bluetooth, but it does require its very own 'wall-wart' for power. The monitor, as its name implies, gives real-time indication of gas/electricity consumption, plus a graph showing previous usage.
It also features a traffic light system, Red, Yellow and Green which denoted the level of ELECTRICITY being consumed real-time. I find that most useful as its red when the tumble dryer is on and changes to yellow or green when it has finished it's cycle. As the dryer is in our garage, it saves me the effort of checking to see if I can get the washing out!!!