I have some image files for iPhone 5 size 640x1136, i have previously implemented retina images for iPhone 4 & 4S using @2x suffix, so what will be the suffix for images
It’ll still use @2x images where they’re available. There’s a -568h suffix you can use for the launch image, as in Default-568h@2x.png, but that’s currently the only place it’s supported; see Leo’s answer for a way to get that working elsewhere.