This is first app for macOS with graphics user interface for "esptool.py". With this app you can easily and simply change the firmware in wireless module ESP8266. No more typing of commands in the terminal. A few clicks and firmware save in the ESP8266 module. If you want to use the application, you must first install the "esptool.py" script. Information how to install "esptool.py" it can be found on the internet, and my web site.