LostGeometry.xyz - Huge set of 91 abstract 3D objects in various styles.
Viz4D - Viz4D helps you create top-performing web-based 3D viewer that works great on mobile and VR. It is tailored for real-time Archviz walkthrough, 3D product configurator and presentation.
Womp - 3D Made Easy
Sketchfab VR - Explore countless user creations from Sketchfab in virtual reality.
Spline - Design tool for 3d web experiences
Sketchfab - Sketchfab is an industrial design software tool is useful for ideation and for beginners in the industrial design field.