The Peek Mobile Device was a "phone killer" from some years ago: https://en.wikipedia.org/wiki/Peek_(mobile_Internet_device) It did email, text, some basic social networking, and maps. The device itself could be purchased cheaply with a plan, or relatively expensive with no plan, no fees. They ran on T-Mobile's M2M network and worked fairly well. I had one for several years, was nice not having a phone bill. The company had issues remaining fiscally solvent, and after some stumbles they shut down one day without warning. The devices themselves were great little doodads, and I wish that there had been some other way of doing something with them. Just wasn't worth the time to reverse engineer what was a very slow ancient device. Meshtastic, the devices in the article, still requires an input device. They're basically a P2P beeper that you use your smartphone to access.