Best PCOS Apps: What Each One Tracks and What It Costs

Is there actually a “best” PCOS tracking app?

Not one — a best way to pick yours. Every general-purpose period app is built around a roughly 28-day cycle and a single mid-cycle hormone surge. PCOS routinely produces neither, so the real question is three narrower ones: does it handle your actual cycle length, what does it do with data you would not want anyone else to have, and what does it cost past the free tier. This page answers all three for six apps people with PCOS actually use.

Why a 28-day model breaks on a PCOS cycle

In a study of 2,111 community women and 506 hospital patients in Beijing, the most common cycle length among those with PCOS was 35–60 days in the community group and over 60 days in the hospital group — both comfortably outside the 21–35 day range most calendar algorithms are tuned on. An app that predicts your next period 28 days out is not being cautious; it is applying someone else’s cycle to yours.

That single fact is the reason a PCOS-specific answer to “which app” looks different from the general answer. It also means an app’s cycle-length math matters more than its symptom list, its colour scheme, or its community forum.

Six apps, compared

Flo: the broadest symptom log, and a federal privacy order on file

Flo lets you log dozens of symptoms alongside your cycle in one place, which is its real appeal — it is trying to be the single app for period, mood, skin and sleep tracking at once. It is also the subject of a 2021 FTC settlement: the agency found Flo had shared sensitive health data from its Period & Ovulation Tracker with Facebook and Google despite promising not to, and the final order requires Flo to get affirmative consent before sharing personal health data and to undergo an independent privacy review.

After the 2022 US Supreme Court decision overturning Roe v. Wade, Flo added an “Anonymous Mode” that lets you use the app without your name, email or advertising identifiers attached. It requires a paid subscription, and your entries are still stored on Flo’s servers — anonymous mode changes what is attached to your identity, not where the underlying data lives.

Clue: built for irregular cycles, and says it does not sell your data

Clue ships a feature literally called Irregular Cycles, designed to widen its prediction range instead of assuming a near-28-day pattern — the single most PCOS-relevant feature on this list. Clue is made by BioWink GmbH in Berlin, stores data on EU servers, and its privacy policy states that the health data you track “is never shared with or sold to advertisers.” Clue does not measure temperature or read a strip itself, so it cannot confirm ovulation the way Fertility Friend or Natural Cycles can — it tells you what your calendar and symptoms suggest, not what your body has already done.

Premom: AI strip-reading, undercut by PCOS biology and a 2023 settlement

Premom’s core feature is genuinely useful on paper: point your phone camera at an ovulation strip and it reads the line for you. The problem is the strip itself. Standard urine LH tests read positive above a threshold of roughly 25–30 mIU/mL, a level built around a sharp rise from a low baseline. In PCOS, that assumption does not always hold — one study of 119 women with PCOS found an LH:FSH ratio above 2 in 45.4% of them, meaning nearly half were sitting on a baseline high enough to blur or fake a surge reading, regardless of which app or brand of strip is doing the reading. Premom cannot fix that; no strip-reading app can.

Premom’s developer, Easy Healthcare, separately settled with the FTC in May 2023 over sharing users’ health data with Google, an ad-analytics firm, and two companies in China, without the consent its privacy policy promised. The settlement banned the company from sharing personal health data for advertising going forward and required it to ask those third parties to delete what they had already received.

Natural Cycles: the one that gives you more caution, not less

Natural Cycles is FDA-cleared as a form of hormone-free birth control, using a daily temperature reading and an algorithm rather than a calendar guess. It is honest about what an irregular cycle does to that algorithm: it widens the fertile window and produces more “red” days requiring backup protection, not fewer. That is the correct response to genuine uncertainty, but it means Natural Cycles is a worse fit if you were hoping an irregular-cycle-aware app would hand you more green days — it will not, because it cannot know what it does not yet know about your cycle.

Worth noting for context: Natural Cycles’ own consumer content already refers to polyendocrine metabolic ovarian syndrome (PMOS), the new name PCOS was given in a 2026 global consensus published in The Lancet. Same condition, same diagnostic criteria — only the label changed, and this article uses PCOS throughout because that is still what most readers search.

Fertility Friend: no calendar guess at all

Fertility Friend does not predict your next ovulation date; it identifies, after the fact, when your temperature and cervical fluid pattern show ovulation already happened. Its own guidance for PCOS charting says cycles are “often long,” temperatures “may be rocky,” and you may see several patches of fertile-looking cervical fluid before ovulation is actually confirmed — which is an honest description most calendar apps do not offer. The tradeoff is effort: a daily temperature reading, taken at a consistent time, for as long as your cycle runs.

Ovia Health: a workplace benefit, with real limits on what it shares

Ovia works like Flo — calendar and symptom based — but is more often encountered as an employer benefit than a personal download. As of its 2025 policy update, Ovia states it does not sell or share personal data for advertising and does not pass sexual-activity or community-feature data to employers. It does share a summarised view of your tracked health data with an employer’s care team, but only for users who separately consent to that sharing, and only for care-management purposes, not employment decisions.

What about apps built specifically for PCOS?

A newer category of PCOS-only trackers exists, built around a wide cycle-length range from day one rather than retrofitted onto a mainstream app. Treat them with more caution, not less: most are recent, small-team products without the years of security scrutiny — good or bad — that Flo, Clue and Premom now have. Read the privacy policy yourself before choosing one, and confirm it lets you delete your data on request.

Does your phenotype change which app is worth using?

Somewhat. If your PCOS is insulin-driven with a 35–60 day cycle, Clue’s Irregular Cycles mode or Fertility Friend’s chart-based confirmation will track reality more closely than any calendar app tuned to 28 days. If your cycles run past 60 days or stop entirely for stretches, no app can generate a prediction from an event that is not happening — that pattern is worth raising with a clinician rather than solving with a different download. If you are actively tracking ovulation to conceive, pair whichever app you pick with a method that confirms rather than only predicts, since a predicted date you never actually reach is worse than no date at all.

Not sure which phenotype pattern fits you? The three-minute quiz is a faster starting point than trial-and-error with five different apps.

What none of these apps can do

No app here diagnoses PCOS, replaces a blood panel, or confirms ovulation with certainty from symptoms alone. If your periods have stopped for 90 days or more, or you have never had a spontaneous period off hormonal contraception, that is a conversation for a clinician, not a longer tracking history.

More product comparisons like this one live in the reviews section, including a deeper look at which trackers actually handle a 60-day gap rather than just accepting the number.