This App is the mobile version of a card trick. It is able to determine a number between 1 and 100 based on only seven cards. Each card contains a subset of numbers between 1 and 100.
Please ask someone (or yourself) to memorize a number between 1 and 100, whereas 1 and 100 are valid choices. Afterwards you are going to show this person seven different cards with random numbers.
For each card your counterpart (or you) needs to say if the memorized number is included on the specific card. The answer can be either Yes or No and the corresponding answer should be confirmed with the Yes or No buttons underneath each card.
After answering the seven questions with Yes or No, a result page is displayed, where you can click the Abracadabra button in order to show the result. Before you press the button you might want to use a spell in order to create some tension.
Lets impress your friends with this legerdemain or just enjoy this magic trick yourself.