PanesManager extension developed by David Oudart is available in Extension Registry. It adds two buttons in the statusbar of the interface (bottom bar) to toggle the Sidebar (left pane) and the Navigator (right pane) of the window. This extension is open source and hosted on Github (https://github.com/pixdad/PanesManager). Thanks to David.

DDL (Data Definition Language) generation extension developed by Minkyu Lee is available in Extension Registry. It allows you to generate DDL from a data model (ERD). This extension is open source and hosted on Github (https://github.com/niklauslee/staruml-ddl).

An extension for generating getters and setters developed by Minkyu Lee is available in Extension Registry. It allows you to generate getters and setters for selected attributes or selected classes. This extension is open source and hosted on Github (https://github.com/niklauslee/staruml-gettersetter).