Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Qlone - 3D scan any object with your iPhone or iPad
FreeCAD - An open-source parametric 3D modeler
Drawing Desk - Drawing Desk Draw Paint Color, Doodle and Sketch Pad created and published 4Axis Technologies for Android and iOS devices.
Sculptris - Sculptris: Enter a world of digital art without barriers.
DWG FastView - DWG FastView for Windows is a lightweight dwg/dxf drawing viewer and editor produced by Gstarsoft, no need of dwg format conversion, vector graph magnified without distortion and full compatible with AutoCAD DWG/DXF.