SolidWorks eDrawings - SolidWorks offers complete 3D software tools that are easy to learn and use, and work together to help you design products better.
Morpholio Trace - Morpholio Trace is widely called to be the dream software of the designers and architect.
SketchUp - 3D for Everyone
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.
SketchBook - SketchBook is a professional drawing or painting application that allows designers, architects, and concept artist to sketch their ideas and create adorable illustrations in no time.
Drawing Desk - Drawing Desk Draw Paint Color, Doodle and Sketch Pad created and published 4Axis Technologies for Android and iOS devices.