Read
- Developer of Popular Women’s Fertility-Tracking App Settles FTC Allegations that It Misled Consumers About the Disclosure of their Health Data;
- Lawsuit claiming Flo Health app shared intimate data with Facebook greenlit as Canadian class action;
- Google, Flo Health to pay $56 million in period-tracking app privacy case;
- Menstrual tracking app data is a ‘gold mine’ for advertisers that risks women’s safety;
- You Give Apps Sensitive Personal Information. Then They Tell Facebook
Android:
iOS:
PrivacyGuides has a section about this on their website: https://www.privacyguides.org/en/health-and-wellness/#menstrual-cycle-tracking
At the time of writing, it seems Drip is the best option on both iOS and Android. The app is free, open-source, and all data is completely local. Honorable mention to Euki as well
It’s better to stop using apps to track your period at all.
Use a paper planner, bullet journal, or graph paper. Don’t let any of these companies suck up your personal data.
This might work OK for simple period tracking, but for more advanced fertility tracking, it’s not really possible to do pen-and-paper without being a huge pain.
For example, the open-source, local-only app Drip optionally uses a “sympto-thermal method” to estimate when a user is fertile; the app takes not just the days they are on their period into account, but also their body temperature, cervical mucus values or cervix values, and throws those inputs into an open-source algorithm for much more accurate results.
Doing all that on pen and paper might be possible, but it would also be a bit of a nightmare.
BlueMoon and Periodical can also be found on the F-Droid app store, no need for Google Play Services:
https://f-droid.org/packages/ch.nilsgrob.android.bluemoon
https://f-droid.org/packages/de.arnowelzel.android.periodical
I use this one myself, a bit tedious, it’s all front-end so you need to export and import your own data (1 json file).




