Receiving data from arduino

In my arduino code i have integer variable named temperature. It’s inital value is 32 and i am adjusting this variable’s value with 2 button.One button for increment other button for decrement.I want to send this variable value to Mit App Inventor.I couldn’t do that in the good way.In one way it writes continuosly to the right, another way it writes continuosly to down.In the last way it works quite good but delay cause to my arduino program crash. If you want i can share full arduino code.

Here is my tryings on arduino :
1 - Serial.println(temperature);

2 - Serial.print(temperature);

3- Serial.println(temperature);

Here is my codeblocks :

Please see the Delimiter article in FAQ

Be sure to use println() at the end of each message to send from the Arduino, to signal end of message. Do not rely on timing for this, which is unreliable.

Also, return data is not immediately available after sending a request,
you have to start a Clock Timer repeating and watch for its arrival in the Clock Timer event. The repeat rate of the Clock Timer should be faster than the transmission rate in the Arduino, to not flood the AI2 buffers.

In your Clock Timer, you should check
Is the BlueTooth Client still Connected?
Is Bytes Available > 0?
IF Bytes Available > 0 THEN
set message var to BT.ReceiveText(-1)

This takes advantage of a special case in the ReceiveText block:

Receive text from the connected Bluetooth device. If numberOfBytes is less than 0, read until a delimiter byte value is received.

In the AI2 Designer, set the BlueTooth Client Delimiter byte to 10.

Thanks for your answer.I am gonna try your suggestions but I don’t understand your suggestions totaly , I’ll watch your tutorials about that and I think i can i understand your suggestions