What are some alternatives?
When comparing pgModeler and MySQL Workbench, you can also consider the following products
DbSchema - DbSchema - ER Diagram & SQL Database Tool
DBeaver - DBeaver - Universal Database Manager and SQL Client.
DataGrip - Tool for SQL and databases
ERBuilder - ERBuilder is a data modeling software that provides all the features you would expect from a professional database modeling tool such as reverse engineering, generating DDL scripts and databases, generating data, comparing models & databases and more
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.
Sequel Pro - MySQL database management for Mac OS X