*.+ What is the Period Prediction/Period Management App "Rhythm Diary"? *.+
This is a free period prediction/period management app that provides various information based on menstrual data, including recording and managing the menstrual cycle, which is important for women, predicting fertile and infertile periods, providing diet support, and offering advice on symptoms and lifestyle changes based on bodily changes.

The Period Prediction/Period Management App "Rhythm Diary" has surpassed 4 million downloads ♥
In addition to period management, you can also manage basal body temperature, weight, body fat percentage, and schedule for free ♥
"Rhythm Diary" is the only period management app that can do all this!


Registration of menstrual start date / Registration of menstrual end date / Prediction of next menstrual period and ovulation date / Explanation of menstrual cycle / Prediction of pregnancy possibility based on menstrual data / Your current index based on your period data: "Discharge Index," "Skin Index," "Body Index," "Irritability Index," "Diet Index," etc.


Peace of mind even when changing devices! With Rhythm Diary ID registration, you can use "automatic data backup" indefinitely. You can smoothly transfer your important data such as menstrual start date, menstrual end date, ovulation date, basal body temperature, weight, and body fat percentage.


In addition to checking the next predicted period date, you can easily check past menstrual start and end dates, check the possibility of pregnancy based on menstrual data, manage your health including mood swings, physical discomfort, swelling, dizziness, irregular periods, and irregular bleeding, and register schedule icons related to your period.


If you find out you're pregnant, "Maternity Mode" is recommended! You can use the following functions without deleting your important menstrual start and end date data! Explanation of physical condition for each week of pregnancy / Lifestyle advice tailored to changes in the mother and baby / Record of prenatal checkups / Notification function for checkup appointments / Ultrasound image saving / Viewing of ultrasound image album / Record of health management specific to pregnancy


Basal body temperature registration / Graph display (image saving also possible)
You can check the fertile and infertile periods based on past menstrual start dates, comparing them with your basal body temperature. Perfect for fertility planning!


Menstruation and weight are closely related! It's also recommended for dieting, targeting periods when weight loss is easier!
Weight registration / Target weight setting / Graph display (image saving and external data transmission also possible) / You can also check weight changes associated with pregnancy using a comparison graph of normal and pregnancy periods (※When using in maternity mode)