From the project's overview page:
The name pgModeler is an acronym of PostgreSQL Database Modeler and refers to an open source database modeling tool specially designed for PostgreSQL Relational Database Management System. This software reunites the concepts of entity-relationship diagrams and the features that PostgreSQL implements including its extensions of the SQL standards.
The tool is full featured and permits user to quickly create reliable database models and export them into several modes, from PNG image to SQL scripts as well directly to a running server. The overall features available does not stands only on modeling and exporting. Having a huge set of features this software is capable of reverse engineering existing databases producing their conceptual representation, it also compares models and databases generating SQL scripts that can be used to synchronize the database to the most recent model version.
From pgModeler's GitHub repository:
No more DDL commands written by hand let pgModeler do the job for you!