SSPX 7.1 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. This free software for Mac OS X was originally designed by Nestor Cardozo. SSPX for Mac relates to Education Tools.
From the developer:
SSPX is a program to calculate strain/strain rate from displacement/velocity data in two and three dimensions. SSPX is a full fledged inverse modeling program to calculate best fitting deformation tensors given displacement or velocity vectors at a minimum of three points in two dimensions, or four points in three dimensions.
You may want to check out more software for Mac, such as Trapcode Particular, Xfoil or DesignWorks Professional, which might be similar to SSPX.