CumuCloud File Manager for Google Sites & CumuCloud File Manager for Google Docs projects started due to an internal need. We use both Google Sites & Docs, and we found them to be very useful, however when you want to perform bulk actions you face a real problem.
While Google Docs allow multiple file upload, it does not allow folder structure upload. Google Sites does not allow even that. Fortunately Google released API for both services allowing 3rd parties to build utilities for those services.
CumuCloud File Managers are FTP-like clients which uses Google services APIs to integrate with them and allow the user an easy way to upload & download files from Google sites & Google docs.