Microsoft Azure IoT Hub - Basic - B1 - fee - 1 unit per day

Connect, monitor, and control millions of IoT assets running on a broad set of operating systems and protocols to jumpstart your Internet of Things project with the IoT Hub. Enhance security of your IoT solutions by using per-device authentication to communicate with devices with the appropriate credentials. Securely establish reliable, bi-directional communication with these assets, even if they are intermittently connected, to analyze incoming telemetry, synchronize device management workflows, and send commands and notifications as needed.