This is very simplistic plugin that let's you generate PDF file with cards that you might print, cut and place on your scrum/kanban board.
You can navigate to url <your JIRA base url>/plugins/servlet/yakuza/cardsprinter, so if you access jira by URL: https://example.com/jira, then type: https://example.com/jira/plugins/servlet/yakuza/cardsprinter. Then type JQL query, press Enter and below all issues, there will be "Print" button.
Otherwise you can directly perform GET request on resource: <JIRA base url>/plugins/servlet/yakuza/cardsprintpreview?jqlQuery==<urlencoded JQL query> which in turn will return application/pdf with issues matching given query.
To generate PDF files PDFBox is used.