Here's how you can download a free app that will let you use the OS X Finder to see your iCloud files.
1. Go to the Plain Cloud site.
2. Click on the download button.
3. There is also an optional Donate button to thank the developer for this free iCloud software.
Here is the official description of the Plain Cloud app:
"Simple access to your iCloud ”
With Plain Cloud, you are able to access your iCloud with the Finder. Just click the specific App and you will see all documents in a new Finder window.”"