card piles

21 card trick

I made another iOS app. This one is a “magic” trick. Actually, it’s just process of elimination by restructuring a 2-dimension array. It’s the 21 card trick.

I had learned this one nearly 30 years ago from a friend in middle school.

At any rate, have at it.


Feel free to use card piles at your leisure for whatever purpose you have in mind.


All card piles purchases are final. I cannot issue refunds charged to your Apple ID, but you can ask Apple to do so.

For Entertainment Only

card piles is not intended for, and should not be used for any sort of betting.


Data Collection

card piles does not collect any data.

Data Sharing

Given the above point, card piles cannot share data. card piles is a SwiftUI app and makes use of Apple’s developer libraries exclusively; no external libraries. These Apple libraries do not, to the best of my knowledge, collect data.

Data Retention

Since card piles does not collect data, card piles cannot retain data.


There’s not much that can go wrong with card piles. That said, if after restarting your device and reproducing the issue you think you’ve found a bug, please reach out; I don’t like bugs either.