I couldn't find anything in the article on which CGM he's using. Anyone know?

I recently switched to the FreeStyle Libre which you use by pulling readings from over NFC to a cellphone. I'm not clear on what the nice 'real' CGMs are like these days or how they work (as far as connecting to one's body).

I like the way the Libre connects (small disk that sits on the back of your arm for two weeks at a time), so if the CGMs which transmit with bluetooth are more bulky/less convenient, I'd almost be tempted to build a little NFC to bluetooth device, Fitbit-sized, which could be strapped over the Libre sensor and scan it every minute or so and stream data to my phone.