Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
FreeCAD - An open-source parametric 3D modeler
MIT App Inventor - App Inventor is a cloud-based tool, which means you can create apps for phones or tablets right in your web browser.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.