I had only good experiences with Boxcryptor as a stand-alone application in Windows, but when trying to use it as an extension in Chrome it didn't work. All I got upon logging in is, "Warning! Native client doesn't seem to work correctly in your browser. Some features of Boxcryptor had to be deactivated." Needless to say, it then didn't do anything.
Now I'm switching to Chrome OS and would like to continue with Boxcryptor, but it is only available as a Chrome extension. Hence, Boxcryptor is not usable in Chrome, Chrome OS, Chromebooks, Chromeboxes, Chromebases or Chromebits. Bummer. Looking for alternative.