ESP8266Flash 1.0.2 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free software for Mac is Marcin Gibas.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The software lies within System Tools, more precisely Device Assistants.
From the developer:
ESP8266Flash is a graphical user interface for "esptool.py". With this app, you can easily change the firmware in wireless module ESP8266. If you want to use the application, you must first install the "esptool.py" script. The application does not contain any configuration panels. All necessary data is set in the main window of the program.
You may want to check out more Mac applications, such as ecoDrive, Internet Connection Keeper or RAGE SERank, which might be related to ESP8266Flash.