draw.io - Online diagramming application
Palette CAD - Palette CAD is one of the easiest 3D design software for those people who want to use a simple to use program for interior designs.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.