Update meta viewport tag's content for fit page width. ios and android safe.

gistfile1.coffee

viewport = document.getElementById('viewport')

orientationchange = (event) ->
  unit = "width"
  current_orientation = window.orientation
  wider = window.screen.width > window.screen.height

  if (current_orientation == 180 and wider) or
   (current_orientation == 0 and wider) or 
   (current_orientation == -90 and !wider) or
   (current_orientation == 90 and !wider)
   unit = "height"

   unit = window.screen[unit]

   if (unit > 700)
    ratio = unit/1032
    viewport.setAttribute('content', 'width=1032, initial-scale='+ratio+', maximum-scale=' +ratio + ', user-scalable=yes')
  else
    viewport.setAttribute 'content', 'width=device-width, initial-scale=1.0, user-scalable=no'

  $(window).bind 'orientationchange', orientationchange
  orientationchange()