Periodical
Periodical Summary
Periodical is a mobile Android app in Health And Fitness by Arno Welzel. Released in Apr 2012 (13 years ago). It has about 25K+ installs and 158 ratings with a 4.49★ (good) average. Based on AppGoblin estimates, it reaches roughly 1.2K monthly active users . Store metadata: updated Nov 17, 2025.
Recent activity: 646 installs this week (1.6K over 4 weeks) showing exceptional growth View trends →
Store info: Last updated on Google Play on Nov 17, 2025 .
4.49★
Ratings: 158
Screenshots
App Description
A menstrual calender with calculation of fertile days according to Knaus-Ogino.
This application calculates the fertile days according to Knaus-Ogino and can track menstrual symptoms.
WARNING: It is not recommended to use this calendar to avoid pregnancy! There are more accurate methods, like measuring the basal body temperature.
The data can be backed up on a memory card or "internal" memory, if present.
If you have any further questions or want to help me with translations in other languages, please contact me via e-mail - thank you.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
You can obtain the source on my website.