MatterControl - MatterControl is a free, open source app that lets you organize and manage your 3D prints.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Slic3r - STL-to-GCODE translator for RepRap printers Here comes Slic3r! Its features are: - speed
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.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.