8 Clue App Alternatives for Tracking Periods, Fertility, and PCOS

Clue, from Berlin-based Clue GmbH, has spent years positioning itself as the research-driven, science-backed alternative to more casual period trackers — it partners with universities, publishes studies using its aggregated data, and markets itself on rigor rather than pink-and-flowers branding. For a lot of users that’s exactly the pitch they want.

Two things still send people looking for alternatives. First, Clue’s predictions are still fundamentally calendar-based: they average your recent cycle lengths and forecast forward, which works well for fairly regular cycles and gets progressively less reliable the more your cycles vary — which is exactly what happens with polycystic ovary syndrome (PCOS), where cycles can run anywhere from 35 to 90-plus days and ovulation is often irregular or absent. Second, Clue has moved more of its features behind a Clue Plus subscription over time — cycle predictions, advanced insights, and PMS forecasting are increasingly paywalled, which has pushed some long-time free users to look elsewhere.

Below are eight alternatives, in order of how directly they solve the “Clue isn’t built for my cycle” or “Clue keeps paywalling things” problem, rather than in order of popularity.

1. Cora — PCOS Tracker

Cora is built specifically for PCOS rather than adapted from a general cycle tracker, which is a structurally different starting point than Clue’s. Where Clue’s algorithm treats a 50-day gap between periods as an outlier to average against future predictions, Cora treats that gap as expected data and shifts its attention to the symptoms surrounding it instead of trying to force a regular-cycle model onto irregular data.

In practice:

Symptom tracking built around the PCOS presentation. Acne, hirsutism, scalp hair thinning, weight change, mood, fatigue, and sleep are tracked as core daily inputs alongside cycle length, not as an optional add-on to a flow calendar.

Logging structured around the recognized PCOS phenotypes — insulin-resistant, inflammatory, post-pill, and adrenal — so what the app asks and what it surfaces is relevant to how PCOS actually differs between people, rather than one generic chart applied to everyone.

No baseline assumption of a “typical” cycle. Because irregular or absent ovulation defines the condition for many people, Cora doesn’t quietly flag irregularity as an error state the way calendar-first apps tend to.

Appointment-ready reporting — a summary of cycle and symptom patterns over time built to be useful in a short visit with a gynecologist or endocrinologist, rather than a raw log a clinician has to interpret from scratch.

PCOS-specific education — content on phenotype differences, what’s actually established about causes (see our piece on what causes PCOS), and how PCOS overlaps with and differs from other conditions.

If your issue with Clue is that its “science-backed” predictions still don’t know what to do with an irregular cycle, this is the direct fix — irregularity is the default case Cora is designed around, not an edge case being tolerated. If you’re figuring out what to actually log day to day, our guide on tracking PCOS symptoms for a doctor’s visit covers the specifics.

2. Flo

Flo is the most-downloaded period tracker worldwide and a natural comparison point to Clue — both are general-purpose, calendar-driven trackers with broad symptom logging. Flo leans harder into AI-driven personalized insights and a broader wellness content library; Clue leans harder into published research partnerships. Functionally, for cycle prediction purposes, they have the same underlying weakness: both extrapolate from cycle history, so both get less accurate the more irregular your cycles are.

Flo also carries its own baggage — a 2021 FTC settlement over data shared with third-party analytics platforms despite promises otherwise. We cover this, and six other alternatives, in more detail in our Flo app alternatives article, which is worth a read if privacy is your main concern rather than cycle regularity specifically.

3. Ovia Fertility / Ovia Health

Ovia is a suite of three linked apps — cycle, fertility, and pregnancy — distributed widely through U.S. employer and health-plan benefits programs, which is how many people first encounter it. It offers fertile-window prediction, ovulation tracking, and integration with employer benefits navigation where available, and is typically free to the end user because it’s funded through those employer programs.

The trade-off: employer-sponsored health apps raise their own data-visibility questions, since usage can be accessible to a benefits administrator even where it isn’t shared with the employer directly. If you’re leaving Clue partly over data concerns, Ovia doesn’t necessarily solve that — it just shifts who’s on the other end of the data.

4. Natural Cycles

Natural Cycles is FDA-cleared as a form of contraception in the U.S. and CE-marked as a medical device in the EU — a level of regulatory backing none of the other apps here have. It works by combining a daily basal body temperature reading with an algorithm that classifies each day as fertile or infertile, and it’s used both for avoiding pregnancy without hormonal methods and for conception.

It’s a strong choice if regulatory-cleared accuracy matters to you specifically. It’s weaker for PCOS: the algorithm depends on detecting the temperature shift that comes with ovulation, and when ovulation is irregular or absent for stretches, the app has less reliable signal — something the company itself acknowledges for users with irregular cycles.

5. Stardust

Stardust differentiates on privacy and product feel — it states it doesn’t sell user data, monetizes through subscription rather than advertising, and layers astrology and lifestyle content over standard cycle tracking. If your issue with Clue is more about paywalling and brand fatigue than cycle accuracy, Stardust is a reasonable lateral move: similar underlying tracking mechanics, different business model and interface.

It isn’t built around PCOS-specific symptom sets or phenotypes, so it inherits the same calendar-based prediction limitations as Clue for anyone with irregular cycles.

6. Spot On

Spot On is Planned Parenthood’s free, ad-free period and birth control tracker. It logs periods, symptoms, and birth control reminders across a wide range of methods, and its educational content is written by the same clinical team behind Planned Parenthood’s other health resources — a level of institutional vetting most independent apps don’t have.

It’s a solid, low-friction pick if you want something free and straightforward with a trusted name behind it. Like Clue, it’s a general tracker rather than a condition-specific one, so PCOS-driven irregularity isn’t specifically accounted for.

7. MyFLO

MyFLO, built by functional nutritionist Alisa Vitti, organizes itself around daily hormone fluctuation across the cycle rather than cycle length alone, pairing that with food and lifestyle recommendations tied to where you are in the cycle. It touches on PCOS in its content and includes a program aimed at hormonal balance.

It’s fundamentally a lifestyle and nutrition tool first, not a symptom-tracking-and-clinician-report tool — worth knowing if what you actually need out of a Clue replacement is clean, structured data for a doctor’s visit rather than a nutrition protocol.

8. Kindara

Kindara is a fertility-awareness-method (FAM) charting app built around basal body temperature and cervical mucus observation, popular with people practicing FAM for natural contraception or conception without hormonal methods or devices. It’s more manual than Clue — you’re charting observations yourself rather than relying purely on an algorithm’s calendar prediction — which some users prefer specifically because it doesn’t obscure how the prediction is generated.

Like Natural Cycles, it depends on signals tied to ovulation actually occurring on a detectable schedule, so it carries the same limitation for irregular or anovulatory cycles that comes with any temperature- or mucus-based method.

Why cycle irregularity breaks calendar-based apps

It’s worth explaining the mechanism, since it’s the throughline across half of this list. Clue, Flo, Stardust, and Spot On all use some version of a rolling average: take your last several cycle lengths, average them, and project forward. That works when cycle-to-cycle variance is low. PCOS disrupts the input at the source — anovulatory cycles (cycles without ovulation) are common, and when ovulation is delayed or skipped, cycle length doesn’t just lengthen, it becomes far more variable, with the same person seeing a 32-day cycle followed by a 68-day one.

Temperature- and mucus-based apps like Natural Cycles and Kindara have a related but distinct issue: they need the ovulation signal itself (a temperature shift, a mucus change) to actually occur on a detectable schedule, and irregular or absent ovulation weakens that signal.

Neither problem is fixed by a better algorithm on the same data model. It requires an app that treats symptom patterns, not cycle length, as the primary thing worth tracking — which is the structural difference in an app like Cora.

How to choose

Matched to priority:

PCOS-specific tracking and doctor-ready reports — Cora Broadest mainstream alternative, general wellness content — Flo Employer-benefit integration — Ovia Regulatory-cleared contraceptive accuracy with regular cycles — Natural Cycles Privacy-forward with lifestyle content — Stardust Free, nonprofit-backed, straightforward — Spot On Hormone-and-nutrition framing — MyFLO Manual FAM charting, non-algorithmic — Kindara

As with switching away from Flo, it’s common to run two apps at once — a condition-specific app like Cora for daily symptom logging, and a general tracker for anything a partner or existing routine is tied to. The goal isn’t loyalty to one app; it’s getting data you can actually use, whether that’s day-to-day symptom management or walking into an appointment with something concrete instead of “it’s just been irregular.”

Frequently asked questions

Is Clue bad for PCOS? Not bad, but not built for it — its predictions are calendar-based and get less useful the more irregular your cycles are, which is common with PCOS.

Why is Clue paywalling more features? Like most subscription apps, Clue has moved advanced predictions and insights behind Clue Plus over time as its business model matures. It’s a common reason people start comparing alternatives even when the underlying tracking is fine for their cycle.

Can an app diagnose PCOS? No — diagnosis requires clinical evaluation, typically against the Rotterdam criteria (irregular ovulation, clinical or biochemical signs of excess androgens, and/or polycystic ovarian morphology on ultrasound, with two of three required). A good tracker gives you and your clinician better data to work from, not a diagnosis itself.

Do I need to pick just one app? No. Many people track daily symptoms in a PCOS-specific app and keep a general tracker for anything else it’s tied to — there’s no conflict, just double entry.