MQTT Broker

The MQTT protocol is a popular standard that allows devices to communicate using a publish/subscribe pattern. The application responsible for distributing the messages between the devices/clients is called the "broker". Although Android applications typically play the role of the MQTT client in many sensor and IOT scenarios, in some cases it is useful to run the MQTT broker as an Android application (background service). See mqtt.org for more information about the MQTT protocol.
This MQTT Broker app is designed to be a simple background service that can be started or stopped. While running, it will listen on the configured port (defaults to 1883). Also, if the device is rebooted while the MQTT broker is running, the app will start in the background automatically once the device has finished rebooting.

Other MQTT clients running on the same device can communicate with the broker via localhost/127.0.0.1. Remote MQTT clients can communicate via the device's current IP address (ex: a typical WIFI address might look something like 192.168.1.132).