If you have any questions, please contact me at e-mail, not in the comments.
This widget will notify you about a beginning of periods by growing flower. Every your cycle the flower grows up. The clouds comes down a week before menses. If there is a rain over the flower, it means, that menses will start very soon. Calendar opens by taping on the widget. Slide on calendar left to right or right to left to see another month. Push the day if it is critical (this days are marked with red). The days of the next periods is marked with pink (it is automatically calculated). You may export data to text file on SD-card and import it. For example, if you want to migrate data to another device or make a backup. These functions are in the settings.
This is free version. In full version: there is no ad, there is a support of ovulation and fertile period (good for conceiving a child). Also you may set up a password, mark sex and medication and all flowers are available.
IMPORTANT This is a widget, and it is in widgets section on your phone (not in the programs). Please, be attentive.