ZeroPC Cloud Navigator HD
This app is like discovering a whole new OS that not only lives in the cloud but talks to, searches, and integrates with other cloud services - Dropbox, Google Docs, Evernote, Sugarsync, Instagram, etc.
It's free to use unless you want to get more storage or use advanced features. The tablet app allows you to see your cloud accounts, instantly search them, view and download files, and perform all kinds of cloud management all from one place (copying files between cloud services isn't supported yet in the tablet app - you'll have to use the web interface for that).
