Alerting about fire from arduino to phone app

MIT App Inventor Help
,
#1

Hi im struggling with my project for school.

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.

CODE
////////////////////////////////////////////////////////////////////////////
char Option = 0;
Option = Serial.read();

Flame_Sensor_Reading = analogRead(Analog_Flame_Sensor_Pin);

if(Flame_Sensor_Reading>300)
{
digitalWrite(FLAME_LED,HIGH);
Option = "F";
Serial.println("Flame detected");
}
else
{
digitalWrite(FLAME_LED,LOW);
Option = "C";
Serial.println("Clear");
}
////////////////////////////////////////////////////////////////////////////

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.

Any hints? Thanks.

#2

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.

#3

It sends all the variables every time one of them changes, that is, it always sends: sensor1 + "," + sensor2 + "," + sensor3

The app will receive, for example:
45,76,21