Is there any method or application that can make the "Number of Instances/Windows" appear as an overlay on the Finder icon in Dock? I would like to see something like you'd see when you have new mail waiting in Mail or Thunderbird. I would love to get this to work if you have multiple Firefox windows open as well. Would Docktopus work in this situation? It doesn't appear to have a badge that handles the number of open windows or application instances.