Morpholio Trace - Morpholio Trace is widely called to be the dream software of the designers and architect.
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.
Drawing Desk - Drawing Desk Draw Paint Color, Doodle and Sketch Pad created and published 4Axis Technologies for Android and iOS devices.
3DC.io (3D Creationist) - The Easiest 3D Design Platform for Mobile Devices
Morphi - A mobile 3D modeling and design app
DXF View - A lightning-fast drawing viewer enables you to view DXF and DWG™ files on Mac