Retinize It is perfect for designers and front-end developers who need to slice UI-elements from PSDs for iOS or Retina-ready websites.
What is Retina Ready Image
Retina ready refers to a screen on a device that has a high enough pixel density that the human eye can’t make out individual pixels.
The iPhone 6 and iPad 3 are Retina ready. Although Apple owns the term “Retina Ready”, many Android devices now have the same or a higher resolution.