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App · Checked October 16, 2026

Euki

An on-device period and pregnancy log. The publisher says it does not collect tracking data. A nonprofit runs it.

Euki product image
Image: Apple App Store listing for Euki. Checked October 16, 2026.

Verdict

A free period and pregnancy log when you do not want an account.

Reviewed by Jaan Labs, updated October 16, 2026

Best forA free period and pregnancy log when you do not want an account.

Who it's for
People who want English or Spanish, an optional PIN, and a log that stays on the phone.

Euki's homepage calls it the period tracker that doesn't track you, and it quotes Mozilla describing a period and pregnancy tracker. The same page says the app is in English and Spanish, that there is no third-party tracking, and that they do not collect personal data to sell or to use for ads. The FAQ says logs stay on the device, that there is no account or cloud copy, and the app page says the PIN is optional and is not tied to an email or phone number. If you forget the PIN, the FAQ says you redownload the app and start over. If you lose the phone, the FAQ says there is no login that restores the log. Their FAQ also says the app is not designed as a primary form of birth control and that nothing in the app is medical advice. A prediction is not a diagnosis.

Pros

  • The site says the app is 100% free, with no paywalls, and that an independent 501(c)(3) manages the open-source project.
  • The FAQ says logs stay on the device, with no account, and the app page says the PIN is optional.

Cons

  • If you forget the PIN, their FAQ says you redownload the app and start over. A lost phone has no cloud copy to restore.
  • Their FAQ says it is not a primary form of birth control, and a cycle prediction is not a diagnosis.

From the Jaan Journal

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  3. AppStardustPeriod, ovulation, and pregnancy tracking if you also like a lunar frame.