Black White Card is a free utility tool available on the iPhone platform. The app, developed by 鹏 刘, focuses on aiding in baby visual development through the use of black and white cards.

The program instructs users to hold the card approximately 30cm away from the baby, prompting the baby to follow slow movements. Users are advised to switch to the next card after the baby has seen the current one. The training guidelines suggest using 5 to 10 cards at a time, limiting training sessions to no more than 5 times a day for a maximum of 15 minutes.

It is recommended to use the black and white cards only when the baby is in a good physical and mental state. If the baby is not feeling well, usage should be discontinued immediately.