Gzaas is a simple, but useful, tool every teacher needs on their bookmarks bar. Need to share something quickly or spontaneously with your class? Go to Gzaas.com, type what you want to share, and click “gzaas it.” Anything you type will be turned into a full-screen message; no toying around with font sizes required.  Click “share it” to generate a unique URL that you can share any time.  While the auto-generated full screen message are awesome, you can also customize…