Focused on solo activities, Ei Nano serves as a diary for masturbation but is not limited to that.

Wondering about your last session? The dynamic calendar view lets you quickly revisit past activities and better understand your unique cycle.

Let me also explain the features below.

Notes:
* Quickly jot down details about each session.
* Add personal notes to reflect on your experiences and feelings.

Stopwatch:
* You can use the stopwatch for recording.
* No matter how engrossed you become in self-pleasure, starting the stopwatch ensures you won't forget to record.

Calendar:
* You can toggle between statistics/analysis and the calendar view.
* In the calendar, you can view records for each month.

Periods:
* By turning on the feature in settings, you can register your periods.
* Based on recorded periods, it predicts the next period and ovulation day.
* You can check the correlation between self-pleasure and period days.

Share as an Image
* Each section of the statistics/analysis can be shared or sent as an image.
* Feel free to use it for posting on social media, etc.

Date range:
* You can change the period for analyzing statistics.
* Options include All time, Last 7 days, Last 30 days, Last 90 days, Last 180 days, Last 365 days, This year, and Last year.

Backup:
* Supports the built-in "iCloud Backup" on iOS devices.
* Within the app, you can manually back up to Google Drive and restore as needed.

The following data is presented as statistics/analysis.

Last time & Biorhythm:
* You can check the date and time of the last self-pleasure session and its cycle in a line graph.
* Tap each marker on the line graph to check the index for that date.
* If you maintain self-pleasure once a day, the index is 1.00.
* For men, a Harvard University study found that engaging in self-pleasure more than 21 times a month lowers the risk of prostate cancer. With 21 times a month (or 5 times a week), the approximate index is around 0.72.
* The index can be used as a target of 0.72 or to track fluctuations in frequency when it temporarily increases or decreases.
* Unstable biorhythms might be a sign that your body and mind are not in a normal state. Understanding your biorhythm can help with health management.

Day of the week:
* You can check the statistics by day of the week.
* You can also see the total for weekdays and weekends.

Time of day:
* You can check statist