     }
     
     // device property
-    final let screenBound = UIScreen.mainScreen().bounds
-    var screenWidth: CGFloat { return screenBound.size.width }
-    var screenHeight: CGFloat { return screenBound.size.height }
+    final let screenBounds = UIScreen.mainScreen().bounds
+    var screenWidth: CGFloat { return screenBounds.size.width }
+    var screenHeight: CGFloat { return screenBounds.size.height }
+    var screenRatio: CGFloat { return screenWidth / screenHeight }
     
     // custom abilities
     public var displayAction: Bool = true

    
    // tool for controls
    private var applicationWindow: UIWindow!
    private var toolBar: UIToolbar!
    private var toolCounterLabel: UILabel!
    private var toolCounterButton: UIBarButtonItem!

            
            UIView.animateWithDuration(animationDuration, delay:0, usingSpringWithDamping:animationDamping, initialSpringVelocity:0, options:.CurveEaseInOut, animations: { () -> Void in
                
                    self.backgroundView.alpha = 1.0
                    self.resizableImageView.frame = finalImageViewFrame
                
                    if self.displayCloseButton == true {
