The App should be able to check for updates and notify the user if a newer version is available (the running app is outdated).
This is only relevant for versions installed without Java Webstart.
The deployment site for Java Webstart (jnlp.openecard.org) could provide a REST service where the current version can be requested. If the available version is more recent than the one of the running App, the user should be notified that an update is available.
In the richclient, this could be done by colouring the tray icon and providing a description in the status dialog.
Please propose other options and discuss the topic.