So building an app that saves someones home from water damage isn't possible with Apple iOS?

On a device. I am not sure about something. When I put an app into the background and then flip it up to remove it from background is this terminating the app so it will not call BGAppRefreshTask? To get BGAppRefreshTask to be called do I need to put it in background mode and let Apple shut it down after a period of time?

My desired result was to monitor my pool filler and notify the user if for some reason it doesn't shut off and overfills. Any suggestions?

Yes I am trying to move from io.adafruit MQTT to my own server MQTT so I can do push notifications, or txt messages if circumstances arise. Thank you. Any idea of a good free MQTT Broker for mac would be.