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.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.
Affinity Designer - Professional creative software, exclusively for Mac.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.