Indie Boost - A video game discovery software used by Publishers, Press, YouTubers, and Streamers.
draw.io - Online diagramming application
Sketch Isometric Plugin - Generate isometric views from artboards and rectangles
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.
Isometric Love - Cute isometric objects for designers
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.