孕期计算器 is a free iPhone app that allows users to easily and accurately calculate their due date based on their menstrual cycle.

The app calculates the due date by counting 40 weeks (280 days) from the first day of the last menstrual period. It takes into account the month and adds 9 months, as well as adding 7 days to the date. It's important to note that the actual delivery date may differ by 1 to 2 weeks from the calculated due date. If a woman is unsure of her last menstrual period or if her periods are irregular, it is recommended to consult a doctor for a more accurate due date calculation.

In addition to the due date calculation, the app also provides daily tips, action guidelines, information about changes in the mother's body, and information about the baby's development throughout the pregnancy.

Users have reported that the app is highly accurate and helpful. If you're expecting a baby, give 孕期计算器 a try and see for yourself!

Note: The developer's name and contact information have been intentionally omitted to comply with the guidelines.