This cloud storage service offered by Amazon was and is very similar to the one they already have other companies like Apple with iCloud, Microsoft with its Sky Drive, Google with Google Drive or simply Dropbox. However, it lacked a feature that in my point of view was almost essential to consider Amazon Cloud Drive as a worthy competitor to the previous ones, and that is synchronization online.
Now although a little late, it seems that Amazon has realized this and a few days ago you have updated your desktop app with everything necessary to have our content synchronized on our devices, which really makes the whole service make sense.
Also, the fact that the old tools to access disk space in the cloud were written in Java did not help, due to the security problems appeared in OS X with this topic. On the other hand it seems that in this new version have solved this point and the experience provided to the user is already up to the task.
The application is located directly on amazon page, in the form of a small download, which when executed will be synchronized with our Amazon account for later create a Cloud Drive folder in the home directory and in the Finder sidebar. The files that are added to this folder will be automatically synchronized with the Cloud Drive account and with all other systems registered with it.
On the negative side we find that still there is no iOS app so with everything, Dropbox or any other option is even more complete. Hopefully it won't take long to cover all devices.
More information - Amazon launches Cloud Drive manager for OS X
Source - The Verge