See if you can punch computer cards by twisting your fingers into impossible positions, just as programmers did fifty or more years ago.
The app emulates a keypunch - a machine for manually preparing small volumes of punched cards.
In the early days of computing, data was fed into computers on 80-column
punched cards. In the 1950s and 60s large batches of cards were prepared using electronic punch machines, but small volumes were manually punched, using a keypunch. Good programmers could punch cards as fast as they could type ... can you?