This has been asked multiple times here, but without a solid and understandable answer. This is a web-app, not a native-app.
I’m using:
<link rel="apple-touch-startup-image" href="images/startup.png" />
to display the startup image. It loads fine if the image’s resolution is 320×460. I tried using the retina’s resolution which is 640×920 (40px are taken out by the status bar), that didn’t work. I’ve tried the @2x thing, that failed too.
Is it even possible [yet]?
This will add a Splash Screen to your Web App. Below are the sizes you’ll need for both iPad and iPhone/iPod Touch, these include the status bar area as well.
If creating a Web App for iPad compatibility it’s recommended that both Landscape and Portrait sizes are used.