Autodesk has released the Autodesk® AutoCAD 360 official mobile app for Windows 8/RT devices. This is just a free tech preview for Windows Store and it allows you to view DWG, DWF, and DXF files in both the offline and online mode.
•A free CAD viewer for Windows 8.1
•Allows to view DWG, DWF, and DXF files
•Layout control – Switch between model space and paper space
•Support both offline and online mode
•Fully synced with your AutoCAD 360 account
•Allows opening drawings stored on the device or uploading drawings through the AutoCAD 360 web-app at: www.autocad360.com