Tilt Brush - Paint in spaces around you with Virtual Reality
draw.io - Online diagramming application
Oculus Medium - Sculpt, model and paint in virtual reality on a 3D canvas.
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.
MasterpieceVR - Powerful VR sculpting & painting tool
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.