Free 3D CAD software

Nice overview of free CAD and include bonus history of CAD
http://www.freecad.sk/en/

Creo Elements/Direct Modeling Express
https://www.ptc.com/en/products/cad/elements-direct/express
https://www.yumpu.com/en/document/read/12839224/creor-elements-directr-modeling-express-ptccom

Parasolid Modeling on an Ipad. Freemium version available

https://www.shapr3d.com/