iOS: Creating NavigationController lightbox on iPad
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I have been looking at different iPad apps on the market. Yelp for example has the following screen:

![Yelp iPad App][1]


  [1]: http://i.stack.imgur.com/YhtjR.png

Basically, this light box (log in) pops up from the bottom and "hover" over the `UISplitViewController` on the background. 

How do one create this "light box" and animate it in. I am sure there is a non hacky way of doing this, just cannot find anything in my extended knowledge. 
