So xDrip was created to completely skip the Dexcom APIs. With G4 we used a wixel microcontroller, to pass the proprietary radio signal to bluetooth. We'd carry

So xDrip was created to completely skip the Dexcom APIs. With G4 we used a wixel microcontroller, to pass the proprietary radio signal to bluetooth. We'd carry it in our pockets in a tiktac case with a lipo. A graph of our blood sugar would show on our Pebble smartwatches at the time. Once Dexcom built Bluetooth into their transmitters, xDrip was then able to directly pair. There's a lot of smart people on the project, reverse engineering all the Dexcom protocols, and even some other brands of CGM. It does work with Stelo too. xDrip can then sync the data it collects to various APIs/websites. I've been a dexcom user since G4 and never once signed up for a Dexcom account or installed a Dexcom app - the open source stuff was always so much better.