3D Hubs - Airbnb for 3D printing
Unity - The multiplatform game creation tools for everyone.
Zazzy - Design and sell your own 3D printed jewelry
Godot Engine - Feature-packed 2D and 3D open source game engine.
Printful for Messenger - Create and sell print-on-demand merchandise with Messenger
Blender - Blender is the open source, cross platform suite of tools for 3D creation.