Flo

Flo is the world's most popular period and health tracking app, used by over 380 million women globally, with a dedicated PCOS mode that makes it particularly valuable for women with polycystic ovary syndrome. Available free on iOS and Android, Flo lets you log your period — however irregular it may be — track symptoms, monitor ovulation windows, and build a detailed picture of your cycle over time.

For women with PCOS, where cycles can be irregular, absent, or unpredictable, Flo's PCOS mode adjusts its predictions to account for irregular ovulation rather than forcing a 28-day template onto a body that doesn't work that way. You can log PCOS-specific symptoms like excess hair growth, acne, weight changes, and fatigue, and track how your lifestyle habits correlate with your symptom patterns.

Flo also includes a health library with articles on PCOS written by medical advisors, an anonymous community where women with PCOS can connect, and an AI health assistant that answers personal health questions. The premium subscription unlocks deeper insights and predictive analytics.

With its enormous user base, evidence-informed content library, and specific PCOS functionality, Flo is one of the most practical and accessible PCOS management tools available — and its free tier covers most of what PCOS women need from a cycle tracker.