Install dia by entering the following commands in the terminal:
sudo apt update sudo apt install dia
Description:
Diagram editor
Dia is an editor for diagrams, graphs, charts etc. There is support for UML static structure diagrams (class diagrams), Entity-Relationship diagrams, network diagrams and much more. Diagrams can be exported to postscript and many other formats.
Homepage: https://wiki.gnome.org/Apps/Dia/
Version: 0.97.3+git20160930-8
Section: universe/graphics