Bluetooth Module not connecting to App but connected to phone - help!

Projects General Guidance
14

OP might find the following background notes useful.

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

There are some readable pictures therein.

Or try add to or replace loop with

void loop()
{
   mySerial.print("LPG:");
   mySerial.print(MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_LPG) );
   mySerial.print( "ppm" );
   mySerial.print("    ");  
   mySerial.print("CO:");
   mySerial.print(MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_CO) );
   mySerial.print( "ppm" );
   mySerial.print("    ");  
   mySerial.print("SMOKE:");
   mySerial.print(MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_SMOKE) );
   mySerial.print( "ppm" );
   mySerial.print("\n");
   delay(200);
}