The 12.1 version of mathmod 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.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free software for Mac OS X is an intellectual property of Abderrahman Taha. The program lies within Education Tools, more precisely Science.
From the developer:
MathMod is mathematical software for visualizing and animating parametric and implicit surfaces. It is an extension/rewrite of the K3DSurf project. It supports 3D/4D plotting and animation, a scripting language, a JSON file format with a large set of scripted examples, and an OBJ output file of the 3D mesh.
You may want to check out more Mac applications, such as iRNAi, Xfoil or MoonDock, which might be related to mathmod.