At present, there are two kinds of wifi modules on the market, one is wifi to serial port, and the other is wifi to usb. The former is more expensive, but the interface is relatively simple. Basically, all microcontrollers have serial ports. Usb is only available in high-end single-chip computers.

You can consider using serial port module. Through module conversion, there is no difference between communication and serial port. As for the agreement to receive a reply, you can decide for yourself.

In addition, you need to write an Android program on your mobile phone!