(As of Cytoscape 3.7) Support for simple apps will be removed in a future version of Cytoscape, please provide an OSGi bundle app instead.
This is the Cytoscape Swing App API, which supports development of Cytoscape 3.X apps in a manner similar to apps developed in Cytoscape 2.X and provides full access to the Swing specific services of the Cytoscape API in addition to all other services provided in Cytoscape App API.