The key to Hidden spaces is that it's simpler than it seems.

• Drag the hidden spaces stack (with the toggle button & invisible message) to where you want it to be.
• Figure out from under which "rock" you want your invisible message to appear
• Compose your invisible message
• Use one of four methods to reveal your message, one being a custom method that will move aside another stack The four methods are:
  • Body
  • Wrapper
  • Section
  • Stack
  • In addion there are animation options for each method
    • Open Left
    • Open Right
    • Open Down
    • Open up
    • Amimate Slow
    • Animate Fast
    • Scale Up
    • Scale Down
    • Blur Opacity
    • Shadows

Note: I found that this stack doesn't play well with other modals on the page.