XLSTAT 2020.5.1 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.
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 Productivity Tools, more precisely Office Tools. This software for Mac OS X was originally produced by Addinsoft.
From the developer:
The XLSTAT add-in offers a wide variety of functions to enhance the analytical capabilities of Excel, making it the ideal tool for your everyday data analysis and statistics requirements.
You may want to check out more software for Mac, such as Plain Text Editor, pdf-Recover or Apimac Clean Text, which might be similar to XLSTAT.