Studio Designer - Studio Designer is totally different from the traditional designing and home decorating programs.
draw.io - Online diagramming application
Design Manager - Design Manager is an interior designing software that is designed by the leading project management and architecture groups of the world.
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.