To be honest, if the past years since the original iphone are any indication, you never will. Although the processors are capable of displaying it, Apple continues to blame Adobe for several significant instabilities in their OS and thus has stated uncounted amounts of times you cannot play Flash (SWF) content on an Apple device (iPhone/iPod/iPad).
The nature of your SWF is very much the question. Is it animation or video, or do you know?
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