HC-05 bluetooth module - High latency

Projects Networking, Protocols, and Devices
2

I hesitate to answer this because

  1. I have no idea what latency is
  2. This

Is it possible that this latency cause Android app?

is incoherent, and what Android app?
But I would point out that this  bluetooth.begin(115200);is a really bad idea, and may even be the cause of your problem, whatever that might be. It is particularly dumb when you aren't using hardware serial at all. If you must use such a high speed, put bluetooth on pins 0,1 and do it with hardware serial, otherwise stay with software serial and change the baud rate to a maximum 38400.