Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Sketch - Professional digital design for Mac.
Sketchfab - Sketchfab is an industrial design software tool is useful for ideation and for beginners in the industrial design field.
Affinity Designer - Professional creative software, exclusively for Mac.