Icon file for iPhone and iPhone 4 (Does it change?)

Hey I was wondering if I have to do anything else with the 开发者_C百科icon file to make it match the iPhone 4 high resolution retain display? Since you have to do it with the design in the app.

Thanks!

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Yes, you need one that's twice as wide and twice as tall as the standard 57-pixel one, meaning 114-pixels-square.

Apple lists the sizes and appropriate names in Technical Q&A QA1686.