Try this -- have them pick a SECOND card and say you'll get both. The first one (ace of spades) is shown when you open the app. The second appears when they shake the phone.
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richard zadorozny
t11 // cardistry / iphone / developer
I just discovered a bit of a problem. The spectator can't pick the Ace of Spades. Thats the card thats already on the face of the deck. You'll have an AoS rising out of a deck with an AoS on the face.
I just performed this for a friend and he picked the Ace of Spades. Found out you can't do the trick if they do so. Bummer. O well, app still kicks ass.