Kindle Exporter
Kindle Exporter is a plugin for Papers.app designed to export PDF files to the Kindle.
Download
Installation
Place the compiled KindleExporter.exporter in ~/Library/Application Support/Papers/Plugins/Exporter.
Usage
After installing, select the papers you wish to save to the Kindle and click File -> Export -> Kindle. The files will be saved on your Kindle and you may eject your Kindle.