This plugin provides a way to download remote files directly from another http server to the local Pydio installation, without having to transfer the files on the client computer. If it's active and working, it can use the command-line version of the framework to trigger the download in background, allowing the user to disconnect the application totally while the download is running.
It also offer an interesting "bookmarklet" feature, that once activated on any webpage, will add a simple "Download to Pydio" to all the links and images.