wCalFree

wCalFree is a special calendar for tracking period days.
In order to help for medical records, prevent unexpected surprises and plan for future events with all the knowledge. It's a camp assistant for Miss, Mrs or Mr.
An ad-free, enhanced version is also available: wCal.
Instructions:
All operations are done on a month view.
On the opening, the current month is displayed.
Right and left arrows navigate to next or previous month.
Tap on a date: to mark it in red or deselect it.
Current day is written in blue.
Future occurrences will be displayed in purple.
The cycle length automatically refines with the complete history.

WARNING: This App is for iOS 8 and higher.
Keywords : Menstrual calendar, period calendar, cycles, menses.