Servo motor not rotating on signal (but connected, via android bluetooth apps)

I built my project according to this site ->

Kindly give the above link a read first.

I have arduino mega 2560, bluetooth module HC05 and servo motor 9g. I set up everything according to the site above.

When I send signal (0 or 1) through serial monitor, my servo rotates..... but through android apps (including app named: bluetooth terminal), even when my HC05 is connected with app via bluetooth, servo motor does not rotate when I send the signal (0 or 1). Why? All connections are same. Devices are fine. Please help me!!!!

Sorry but lots of information is missing.
Read the first topics telling how to get the best from this forum, how to use this forum.
Most helpers don't have crystal balls, tarot cards or practise mind reading at distance.

Have you tried printing what you get from Bluetooth on your serial monitor? Is it what you think you should get?

No. I dont know how to do that. Looking it up on internet..

do you have knowledge about electronics and programming in C++?

Yes. basic.