I found great tutorial about communication between arduino and phone app here:
but there is one problem.
These messages are sent by click. How to make it so that the app itself scans if the sensor has detected a fire and that this message is sent as a notification/alert to phone.
I tried also this tutorial, but unfortunetly I ended up with displaying every serial line printed in monitor, not only this one placed in if statement.
Well I forgot to mention I know how to do this for 1 variable but I have no idea how for 2 variables, for 1 I simply read serial monitor and the biggest problem with it is that any information coming thrue serial monitor is saved in this variable in app. I want to specify which variable is saved from concrete variable or if statement in arduino.