MQTT is a messaging and connectivity protocol to exchange information from a remote location for Internet of Things (IoT) and machine-to-machine (M2M) technologies.
This app is created for publishing message to the broker by MQTT protocol.
Libraries:
Paho Android Service - MQTT Client Library Encyclopedia
https://www.hivemq.com/blog/mqtt-client-library-enyclopedia-paho-android-service/
https://www.eclipse.org/paho/index.php?page=clients/android/index.php
You can change the stage of the message by click switch button If you want, you can customize it by adding multiple EditText to customize topic, ip, username, password and message by user.
You can check the results of your message by download Mosquitto (local broker) or HiveMQ (online broker)
HiveMQ: https://www.hivemq.com/ Mosquitoo: https://mosquitto.org/