This free open-source app regularly publishes to a configurable MQTT topic whenever connected to a given Wi-Fi network or in proximity to a Bluetooth beacon. It can be used to integrate the presence of your phone in home automation. The app uses the built-in Android alarm manager, so notifications are sent even if the phone is in stand-by. In addition to regularly scheduled checks, the app also reacts to changes in the network connection. The MQTT client supports anonymous and username / passw