Apps to Create UML entities

Diagramo is a robust, open-source web-based diagramming tool perfect for creating flowcharts, graphs, and various diagrams directly in your browser. Built on HTML5, it offers real-time collaboration and flexible export options, making it accessible and versatile.

Freeplane is a powerful and free mind mapping software that allows users to organize ideas, create outlines, and manage information in a hierarchical structure. It leverages the power of visual organization to facilitate brainstorming, project planning, and knowledge management.

Umbrello UML Modeller is a comprehensive, free, and open-source UML diagram tool. It provides robust capabilities for creating a wide range of UML and other modeling diagrams, supporting developers and designers in visualizing complex systems.