It is an IoT App that consists of creating an Mqtt client connected to a Broker in a network with Tasmota or Zigbee2Mqtt equipment. We can add IoT equipment from a predetermined list:
-Sonoff20 (Tasmota)
-TuyaZigbeeSensor (Zigbee2Mqtt)
-AqaraTemp (Zigbee2Mqtt)
-SonoffSNZB02 (Zigbee2Mqtt)
-Xiaomi ZNCZ04LM (Zigbee2Mqtt)
Configuration is very easy as Topics are automatically created and added directly to a Dashboard.

From this link you can see a demo:
https://www.youtube.com/watch?v=_CStETtgtKI

IT IS NOT AN APP FOR ALL USERS!!! You need to have knowledge in IoT... If you are interested, but you don't know where to start, I leave you this link where there are videos that can help you:
https://www.youtube.com/playlist?list=PLAfoA6cZ1I72s6Jc_N0iGBRDbZ6ubbuAH

It is open source and this is the link:
https://github.com/DnomaidGit/AndroidIotMqtt