Air Explorer is an application that manages easily all your cloud servers (Google Drive, OneDrive, Dropbox, Mega, Box, Mediafire, WebDAV, Copy, Yandex, Baidu…). It transfers files between the clouds, synchronizes folders between any cloud or your computer and, optionally can encrypt your files when you upload them to the cloud. Moreover, it supports multiple accounts from the same server.
Here, you have a video where you can see how to install and use Air Explorer.