DBeaver - DBeaver - Universal Database Manager and SQL Client.
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
DataGrip - Tool for SQL and databases
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.