title: How to calculate height of viewable area (i.e., window height minus address & bookmark bars) in mobile Safari for web app?
body: <p>What is the right way to calculate how much viewable space is available on mobile Safari? By viewing area, we mean the amount of the screen actually available to a web app, that is the window height minus the address and bookmark bars.</p>
  
  <p>iOS 7 prevents hiding of the address bar, and we need to properly account for the viewport height.</p>