Retina Ready

Retina Ready is a new standard by the company "Apple"

On retina displays in 1 inc has more pixels because we can create retina ready on retina images displays will be more clear
If you want retina ready in robo.js file write the chosen elements or classes in place of example word
When device pixel of ratio is two then function automatic to selected image file names add @2x For example:

HTML Example
var retina_img = ""; // Default all imgs <img src file.jpg" /> 

OR

var retina_img = "img"; // element or class name all imgs will be <img src="[email protected]" />