Here are the Top 5 Machine to machine  (M2M) applications in the world.

  1. Utility companies
  2. Traffic Control
  3. Telemedicine
  4. Security in Business
  5. Telemetry

Well there are many more applications, i searched in the web for Machine to machine communications in detail and this link is worth reading. They have explained full machine to machine communications from scratch.

Please go through this article link: