A mobile app that tracks periods and reproductive health entirely on-device with no account and no cloud sync

Since the Flo lawsuit revealed period data was sold to Meta, millions of women discovered their most sensitive health data had been shared without consent. The dominant trackers (Flo, Clue) monetize data by design, and the few privacy-focused alternatives (Drip, Euki) are either NGO-built with minimal UX polish or open-source projects with no mainstream traction. This is a privacy-first, polished native mobile app where all cycle data lives only on the device, no account is required, and a paid premium tier unlocks advanced fertility charting and symptom correlation.

Demand Breakdown

928

166

Social Proof 3 sources

Show HN: I made a privacy friendly and simple app to track my menstruation

@stormqueen · 2024-04-29

928 RD

In this age of zero privacy, should we be worried of being persecuted based on our internet activity?

2025-01-01

96 RD

Be mindful of your period data

2024-11-01

Gap Assessment

CompetitiveMultiple tools exist but differentiation opportunities remain

4 tools exist (Flo Health, Natural Cycles, Clue, Drip) but gaps remain: Core business model relies on data monetization; anonymous mode is opt-in and adds friction; data breach and FTC settlement history means trust is structurally broken regardless of UI improvements. No true local-only option.; Requires account and cloud sync by design. Subscription-gated ($13/mo). Does not offer local-only mode. Focused narrowly on birth control use case, not general reproductive health tracking..

Features8 agent-ready prompts

On-device-only data storage

▶

Cycle and period logging

▶

Basal body temperature charting

▶

Fertility window prediction and ovulation tracking

▶

Privacy audit and trust screen

▶

Encrypted local backup and restore

▶

Symptom trends and cycle insights (premium)

▶

Onboarding and no-account setup

▶

Competitive LandscapeFREE

Product	Does	Missing
Flo Health	Market leader period and cycle tracker with 45M+ MAU, AI health insights, symptom logging, and fertility prediction. Has an anonymous mode now.	Core business model relies on data monetization; anonymous mode is opt-in and adds friction; data breach and FTC settlement history means trust is structurally broken regardless of UI improvements. No true local-only option.
Natural Cycles	FDA-cleared birth control app using basal body temperature charting. Hormone-free, medically certified, strong brand around science-based cycle tracking.	Requires account and cloud sync by design. Subscription-gated ($13/mo). Does not offer local-only mode. Focused narrowly on birth control use case, not general reproductive health tracking.
Clue	Science-backed period tracker with detailed symptom and health logging, popular among users who distrust Flo. Berlin-based, positions as privacy-respecting.	Still cloud-dependent with account required. Free tier is limited; premium is subscription. Does not offer on-device-only mode. Privacy claims are policy-level not architectural.
Drip	Open-source, local-only period tracker for iOS. No cloud, no account. Built by volunteers. Covers basic cycle tracking and fertility awareness.	NGO/volunteer-built with minimal UX polish. No Android version. No premium tier or revenue model. Not actively marketed. ~50k downloads, no mainstream traction.