From IntroWizard :
DOWNLOAD FOR FREE TODAY ON ITUNES! Fun sword soundplay action with every whistle in the palm of your hand, have the fun of whistling to your other friends with this iPhone and iPod app. Simply follow the instructions to rip one out. Perfect for a funny introduction, pulling a prank out on an unsuspecting victim, and showing off what cool things your iphone or ipod can do! Lastly, if you can't hear any sounds or sound effects make sure your handset's volume is turned up and the silence switch is off.