How to move the background in unity2d for ios game

I have successfully moved the background with the main character position , but when I build the project for ios in xcode , the screen size is not quite fit with respect to the ios devices screens. I have set up the aspect ratio 19.6 in to game scene , but in ios simulator the background position from left , right , up down is not fit with the actual screen size. I have follow up the this advice http://answers.unity3d.com/questions/639987/setting-up-orthographic-camera-for-2d-iphone-game.html , but no break through for my game.Any step by step tutorial or any video about this issue So please help me in this matter ,

Thanks for considering my question