There are a lot of applications in the appstore with amazing graphics that look great in the iPhone OS 3.x, but it doesn’t look so great using the new retina display of the new iPhone. A lot of them have been released as new applications again but named the same with an “HD” at the end.

You might wonder if that is because there is no easy way to build an application with both HD graphical assets and nonHD graphical assests that looks great on all iPhone OS versions. But that’s not true. Recently I found out a very esy way to do that:

UIKit supports the automatic loading of high-resolution variants (@2x) of your images.

The “only” thing you have to do is generate HD graphical images of each existing image in your current project and name it the same but with an @2x in the end. i.e:

previous image name: logo.png

HD image name: logo@2x.png

once you have all the images just import to your existing project and compile it again using the same iPhone OS version you used to compile the nonHD version of the application, and submit it to the store.

Et voilà! The iOS 4 will handle it automatically to display your new HD images.