QT Cloud Drive is a cross-platform desktop application for connecting to Amazon Cloud Drive. It can be more convenient than using Web-based access because it allows you to remain constantly signed in and allows you to drag and drop files between the cloud drive and other desktop applications.
Easysync allows you to synchronize files among different computers. You pick up a directory you want to synchronize and Easysync will perform synchronisation whenever this directory is changed. The server part propagates the sync signal among clients, so that if there is a change on one client, all other clients will perform synchronization. It is based on Unison.