Apple debuted the Retina display in June 2010 on the iPhone 4. Fast-forward to today and it remains the gold standard for smartphones in terms of crispness and pixel density. Yes, most high-end Android handsets now top the iPhone's 960-by-480 pixel resolution by way of using bigger panels that however don't always introduce denser pixel.
A good example is Samsung's Galaxy Nexus smartphone which has a 4.65-inch display with the native HD resolution of 1,280-by-720 pixels and a pixel density of 316 pixels per inch (ppi), safely above the Retina requirement of at least 300ppi for a smartphone display so the pixels appear indistinguishable to the human eye with a 20/20 vision.
Enter LG's newly-announced five-inch mobile display. It rocks a whopping 1,920-by-1,080 pixel resolution and an astounding density of 440 pixels per inch. If Apple was looking for the perfect display for its rumored five-inch iOS device, this could be it...