CFDTool is described as '(https://www.cfdtool.com) is a fully integrated and dedicated MATLAB® Computational Fluid Dynamics (CFD) Toolbox for modeling and simulation of fluid flows with coupled heat transfer' and is an app. There are more than 10 alternatives to CFDTool for Windows, Linux, Mac, Web-based and MATLAB. The best CFDTool alternative is COMSOL Multiphysics. It's not free, so if you're looking for a free alternative, you could try FEATool Multiphysics or OpenFOAM. Other great apps like CFDTool are SimScale, Code_Aster, Code_Saturne and KRATOS Multiphysics.