Womp - 3D Made Easy
LostGeometry.xyz - Huge set of 91 abstract 3D objects in various styles.
365+ 3D Printing Objects - A year's worth of monetizable 3D printing things.
AstroPrint - Slice, Store, and Print your 3D files from any web enabled device.
Spline - Design tool for 3d web experiences
Celer3D - Collaborative Parameterised 3D Modelling Web Application