Mori
A free, private period tracker for Android that works offline, needs no account, and shows no ads.
What is Mori?
Mori is a free period and cycle tracker app for Android. You log your period in one tap, and the app shows your next period as a date range based on your own cycle history, along with the basis for the estimate and a confidence level.
Mori is built for people who want to track their cycle without signing up or handing over personal details. There is no account or sign-up, no email or phone number required, and the app works fully offline. The app opens straight to the calendar, with no pop-ups, promotions, banners or splash screens. Without optional sync turned on, your records stay on your phone and are not uploaded.
What sets Mori apart is how it handles uncertainty and your data. When your cycles vary, the predicted range widens and the confidence drops, rather than labeling you late. Ovulation estimates appear on the calendar, and reminders stay off until you turn them on. You can export your data as JSON, CSV or a readable summary at any time, and one-tap delete-all removes every record.
Logging, history, estimates, reminders, export and deletion are free. The only paid option is optional cloud sync for moving records to a new phone or using several devices, a one-time purchase of US$3.99. Mori for Android is installed directly as a signed APK from the website, since it is not yet on Google Play; an iOS version is in progress.
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What other founders did to grow.
2722 dispatches from hundreds of founders, pulled from the week's best podcasts.
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Your Actual Audience Will Surprise You — Validate Assumptions With Data Early
Every founder has a mental model of who their user is — and it's almost always wrong in at least one material way. Taylor Wells saw this pattern repeatedly: executives defending audience assumptions that had never been validated by data. At Disney+, over 50% of viewers were single adults on a platform assumed to be for families. Building the habit of asking 'what is this based on?' early prevents six months of product decisions aimed at the wrong person.
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