I received a marketing email about this from Vesternet yesterday and did a bit more research.
I discovered that if you go directly to the Navetas website, you can get a 45 day trial of the kit to see if it works: see
Free TrialIt costs £2.80 (postage) to get the kit and if it doesn't work you can send it back - if you keep it, it costs an additional £70.
So I have taken the plunge and ordered a free trial.
I have an old style (rotary dial / cubic feet) gas meter and I am hoping this will work.
Also, it seems that they are aware of a requirement for an API which hopefully they will release at some point.
I am taking a bit of a flyer on this as it won't work on the electricity front for me as I have Solar PV generation and apparently their system can't differentiate between electricity being generated and consumed. They are developing a solar version.
I am getting it mainly for the gas measurement and of course to see if I can work out a way to integrate it into Indigo