Shapefest - A massive library of 3D shapes for everything!
Icons8 - Free app for Mac & Windows already containing 39,800 icons. Allows to search and import icons…
Isometrica - 3D illustration constructor with 380+ isometric objects
Iconscout - Design Resource Marketplace.
Khagwal 3D Illustration Library - Free 3D illustration library for web & mobile app designers
Craftwork - A collection of User Interface resources made by Craftwork