iCards Prediction

This is an App that can let you easily become a magician.
You can do an amazing magic trick with iCardPrediction.

Effect:
Magician takes out a deck of playing cards and let audience shuffles cards. Audience randomly takes out 5 cards.
After magician intruducing the magic app iCard Prediction, audience input 4 cards by the app, and then the App magically predict the 5th card.
Magician randomly takes out 4 cards from the deck, audience randomly takes out 3 cards and input to the app,and iCard Prediction correctly predict the last card again
Magician lets audience randomly pickup 2 cards to input to the app,and the app still predict the top card of the deck correctly.
When audience thought that the magic is over,magician turnover the device,the screen show up a deck of cards. Magician turns over cards one by one in the app,and show that the sequence of cards in the app are totally the same with the sequence of cards in the real world