I don't know what they used for this project, but I have built similar things with the recently-released Particle Electron that I got on Kickstarter, though now

I don't know what they used for this project, but I have built similar things with the recently-released Particle Electron that I got on Kickstarter, though now I believe it's released widely. Works really great, I was using the Spark Core before, same company and concept but with wifi instead of cellular. https://www.particle.io/cellular https://www.particle.io/cellular