The 1.0 version of PureFluids for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X is a product of PhysChemGeo. The most popular version among the program users is 1.0. We recommend checking the downloaded files with any free antivirus. You can run this free application on Mac OS X 10.8 or later. The application is categorized as Education Tools.
From the developer:
PureFluids calculates the Helmholtz free energy for various pure fluids using equations of state (EOS) collected from the scientific literature. The program allows the calculation of the thermodynamic properties at arbitrary temperature and density or pressure conditions, tables with even spaced increments of temperature and density/volume, or properties at the vapor saturation curve.
You may want to check out more Mac applications, such as ChordPhobia, Learn To Draw or Sibelius 6 Student, which might be similar to PureFluids.