How we make this list: we compare pricing pages, product documentation and public user reviews. Rankite is independent; if a vendor ever pays for a featured spot, that listing is clearly labeled Partner.
Key takeaways
- Only one app here is FDA-cleared as birth control: Natural Cycles, which uses basal body temperature to identify fertile days (annual plan around $150, price not published on the vendor page).
- For straightforward cycle and period tracking, Flo and Clue are the mainstream picks; Ovia and Apple Health Cycle Tracking are free.
- Trying to conceive changes the shortlist: Premom and Kindara are built around ovulation detection, while Natural Cycles has a dedicated pregnancy-planning mode.
- Every app here handles data differently, so check the privacy policy and data-sharing settings before logging sensitive health information.
Quick comparison
| Tool | Best for | Starting price | Free plan |
|---|
 Flo | Users who want one app for periods, ovulation, pregnancy and general health | See website (Premium plans sold in-app) | Yes (free tier with core tracking) |
 Clue | Users who want science-led tracking with a strong privacy posture | See website (Clue Plus sold in-app) | Yes (free tier with core tracking) |
 Natural Cycles | Preventing or planning pregnancy with an FDA-cleared method | See website (annual and monthly plans) | Free demo mode (no ongoing free tier) |
 Kindara | Users who want detailed fertility charting for conception | See website | Yes (free tier) |
 Ovia | Users who want capable fertility and pregnancy tracking for free | Free | Yes (fully free) |
 Glow | Users who want fertility tracking with an active community | See website (Premium sold in-app) | Yes (free tier) |
 Apple Health Cycle Tracking | iPhone users who want cycle tracking without another app or account | Free | Yes (built into iOS) |
 Premom | Users tracking ovulation with test strips who want automatic reading | Free (Premium sold in-app) | Yes (free tier) |
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We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
The best period and fertility tracker apps
Fertility and period apps fall into three jobs: predicting periods, identifying the fertile window, and guiding pregnancy. Most apps do the first two with calendar math, which is fine for regular cycles and unreliable for irregular ones. The serious fertility tools add temperature, cervical mucus or hormone data. These eight cover the full range, from free phone features to the only FDA-cleared option.
#1
Flo
Best for: Users who want one app for periods, ovulation, pregnancy and general health
Visit flo.health
Starting priceSee website (Premium plans sold in-app)
Free planYes (free tier with core tracking)
Flo is the mainstream pick. The app tracks periods, ovulation, symptoms, mood, sleep and more, with modes for trying to conceive, pregnancy and perimenopause. The free tier covers core cycle tracking, and Premium adds advanced predictions, deeper insights and partner sharing. The interface is the friendliest here, which is why it has the largest audience.
The pricing opacity is the annoyance: Premium costs are shown only inside the app, not on flo.health, so we cannot quote a vendor-published price. Predictions on the free tier rely on calendar data, which is less reliable for irregular cycles. If you want temperature-based accuracy, Natural Cycles or Premom are the upgrades.
What we like- The largest user base in the category with a polished tracking experience
- Covers periods, ovulation, pregnancy and perimenopause in one app
- Symptom and mood logging beyond the cycle
Watch out for- Premium pricing is only visible in-app, not on the website
- Predictions are calendar-based on the free tier, which suits regular cycles best
#2
Clue
Best for: Users who want science-led tracking with a strong privacy posture
Visit helloclue.com
Starting priceSee website (Clue Plus sold in-app)
Free planYes (free tier with core tracking)
Clue takes the science-first angle. The app was developed with academic researchers, tracks over 200 symptoms and experiences, and presents cycle data without the gendered design clichés of the category. Privacy is a stated priority, with data stored under EU protections and clear statements about what is never sold. Clue Plus adds predictions, advanced analysis and additional modes.
Like Flo, the paid pricing lives in the app stores rather than on helloclue.com. The free tier handles period and symptom tracking well. Users who want the app to learn from body temperature will need to look at Natural Cycles or a dedicated fertility monitor, because Clue's predictions are calendar-based.
What we like- Developed with researchers and framed around cycle science, not pink aesthetics
- Clear privacy commitments with data stored in the EU
- Detailed symptom tracking with 200-plus options
Watch out for- Premium features are gated behind Clue Plus with pricing only in-app
- Predictions still calendar-based without temperature input
Starting priceSee website (annual and monthly plans)
Free planFree demo mode (no ongoing free tier)
Natural Cycles is in a different category from everything else here: it is a regulated medical device. The app reads basal body temperature, confirms ovulation from the temperature shift, and assigns each day a green (not fertile) or red (fertile) status. The FDA clearance covers its use as birth control, with 93 percent typical-use and 98 percent perfect-use effectiveness reported. The same algorithm runs a pregnancy-planning mode.
The price is not published as a fixed figure on the vendor site; company announcements put the annual plan near $150, sometimes bundled with the NC Band ($129.99 standalone). There is no free tier beyond a demo mode. It also asks for daily discipline: temperature every morning via thermometer, band, ring or watch. For hormone-free contraception or data-driven conception, nothing else here is comparable. For casual period tracking, it is overkill.
What we like- The only app here FDA-cleared as a contraceptive
- Measures basal body temperature to confirm ovulation rather than estimating from calendars
- Modes for preventing, planning and following pregnancy, plus postpartum and perimenopause
Watch out for- No ongoing free tier, only a demo mode
- Requires daily temperature input (thermometer, NC Band, Oura, Apple Watch or Garmin)
- Narrow by design, with no general symptom or mood tracking
#4
Kindara
Best for: Users who want detailed fertility charting for conception
Visit kindara.com
Starting priceSee website
Free planYes (free tier)
Kindara is the charting purist's app. Where Flo and Clue abstract the cycle into predictions, Kindara shows you the chart: basal body temperature, cervical fluid, custom data fields and the patterns across cycles. That makes it the favorite of users practicing the fertility awareness method seriously and of people sharing data with fertility specialists.
The tradeoff is modernity. The interface feels older than the category leaders, and the community is smaller. Pricing for premium features is not published on kindara.com. For trying to conceive with real data rather than calendar estimates, the charting depth is the reason to choose it.
What we like- Charting-first design built around the fertility awareness method
- Tracks temperature, cervical fluid and custom data points
- Strong fit for users working with fertility specialists
Watch out for- Interface is dated next to Flo and Clue
- Smaller user base means fewer community resources
- Premium pricing not published on the site
#5
Ovia
Best for: Users who want capable fertility and pregnancy tracking for free
Visit oviahealth.com
Starting priceFree
Free planYes (fully free)
Ovia is the free full-featured option. Ovia Fertility tracks cycles and ovulation, Ovia Pregnancy follows the pregnancy week by week, and Ovia Parenting continues after birth. There is no premium tier withholding features, which makes it the obvious first try for anyone who wants capable tracking at zero cost.
The consideration is the business model. Ovia partners with employers and health plans, and free health apps earn scrutiny on data practices, so read the privacy policy and settings before logging detailed health data. Feature-wise it is competent across the board without leading anywhere. As a free starting point, it is hard to argue with.
What we like- Completely free with no paid tier gating core features
- Covers fertility, pregnancy and parenting stages
- Employer and health-plan partnerships add clinical content
Watch out for- Free means the business model runs on partnerships and data, so read the privacy policy
- Design and predictions are solid but not best-in-class
#6
Glow
Best for: Users who want fertility tracking with an active community
Visit glowing.com
Starting priceSee website (Premium sold in-app)
Free planYes (free tier)
Glow pairs cycle and fertility tracking with one of the largest trying-to-conceive communities in an app. The forums are the draw: thousands of users sharing experiences, which many people find more supportive than tracking alone. The app itself covers periods, ovulation, symptoms and partner data, with companion apps for pregnancy and the baby stage.
Premium pricing is in-app only, not on glowing.com. The community is peer support, not medical advice, and should be treated that way. For users who want tracking plus a community going through the same thing, Glow is the pick.
What we like- Large community forums for trying-to-conceive support
- Tracks cycles, ovulation, symptoms and partner data
- Companion apps for pregnancy and baby stages
Watch out for- Premium pricing only visible in-app
- Community content is peer advice, not medical guidance
- Predictions are calendar-based
#7
Apple Health Cycle Tracking
Best for: iPhone users who want cycle tracking without another app or account
Visit apple.com
Starting priceFree
Free planYes (built into iOS)
Apple's Cycle Tracking lives in the Health app on iPhone: log periods, symptoms and spotting, get period and fertile-window predictions, and on supported Apple Watch models get retrospective ovulation estimates from wrist temperature. There is no account to create, no subscription and no data leaving the Apple ecosystem unless you allow it.
The limits are scope. Predictions are basic, there is no trying-to-conceive coaching, no community and no Android version. For an iPhone user who wants simple, private cycle logging without handing health data to another company, it is the lowest-friction option available.
What we like- Built into the iPhone with no extra download, account or subscription
- Cycle data stays in Apple Health with on-device processing options
- Retrospective ovulation estimates on supported Apple Watch models
Watch out for- IPhone-only
- Predictions are basic compared with dedicated apps
- No community, coaching or advanced fertility modes
#8
Premom
Best for: Users tracking ovulation with test strips who want automatic reading
Visit premom.com
Starting priceFree (Premium sold in-app)
Free planYes (free tier)
Premom is the conception specialist. Its signature feature is the camera reader: photograph an ovulation test strip and the app interprets the result, removing the squinting over faint lines that defines the trying-to-conceive experience. Cycle tracking, basal body temperature charting and symptom logging support the core job.
The ecosystem leans toward Premom's own test strips, which is worth knowing before committing. Premium features are sold in-app with no published web pricing. For general period tracking it is the wrong app; for ovulation tracking with test strips, the automatic reading is a genuine convenience nothing else here offers.
What we like- Camera-based reading of ovulation test strips removes guesswork from interpreting lines
- Free tier covers core ovulation and cycle tracking
- Purpose-built for trying to conceive
Watch out for- The experience is built around the company's test strips
- Premium pricing only in-app
- Narrower than general cycle apps
How to choose based on your goal
Match the app to the job. If the job is knowing when your period is coming, Flo, Clue, Ovia or Apple Health all do it, and the free options are enough to start. If the job is avoiding pregnancy without hormones, Natural Cycles is the only evidence-backed app option here, and it requires daily temperature logging. If the job is conceiving, Premom and Kindara are built for it, with Natural Cycles as the premium alternative.
Then consider data sensitivity. Cycle and fertility data is health data, and apps have different policies on storage, sharing and sale. Clue publishes clear EU-based privacy commitments; Apple keeps data in its ecosystem; free apps funded by partnerships deserve a careful read of the privacy policy. Whatever you choose, review the app's privacy settings after install: location access, analytics sharing and marketing opt-ins are the usual levers.
Finally, be honest about input discipline. Temperature-based methods (Natural Cycles, Kindara) are more accurate but demand daily logging. Calendar-based predictions (Flo, Clue, Glow free tiers) work with minimal input but assume regular cycles. The best app is the one whose input demands you will actually meet.
How we chose
We started with the categories buyers search: period tracker app, fertility tracker app and ovulation tracker app. For each candidate we checked the vendor's own site for published pricing, verified regulatory claims (only Natural Cycles holds FDA clearance as a contraceptive), and weighted the features that matter for each goal: period prediction, ovulation detection, pregnancy modes and privacy. Where a vendor did not publish pricing on its site, we wrote "See website" rather than quoting app-store prices that change by region.
Frequently asked questions
Which fertility tracker app is the most accurate?
Natural Cycles, because it measures basal body temperature to confirm ovulation and holds FDA clearance as a contraceptive. Calendar-based apps (Flo, Clue, Glow) predict from past cycle data, which is less reliable for irregular cycles. No app is perfect; temperature and hormone data beat calendar math.
Are period tracker apps free?
Most have free tiers: Flo, Clue, Kindara, Glow and Premom all offer free tracking with paid upgrades, while Ovia and Apple Health Cycle Tracking are completely free. Natural Cycles has no ongoing free tier beyond a demo mode. Paid features are usually sold in-app rather than on the vendors' websites.
Can I use a fertility app as birth control?
Only Natural Cycles is FDA-cleared for contraceptive use, and only when used exactly as directed (93 percent typical-use effectiveness). Standard period and fertility apps are not contraceptives and should not be relied on to prevent pregnancy.
Do these apps sell my health data?
Policies differ, which is why you should read them. Clue commits to EU-based storage and states it does not sell data; Apple processes Health data on-device by default; free apps with partnership business models deserve extra scrutiny. Check each app's privacy settings for analytics sharing and marketing opt-ins after install.
Which app is best for trying to conceive?
Premom for ovulation test-strip tracking with automatic reading, Kindara for detailed fertility charting, or Natural Cycles for a temperature-based planning mode. Flo, Glow and Ovia also have trying-to-conceive modes built on calendar predictions, which suit regular cycles.
Sources we checked (8)
- https://flo.health/
- https://helloclue.com/
- https://www.naturalcycles.com/
- https://www.kindara.com/
- https://www.oviahealth.com/
- https://glowing.com/
- https://www.apple.com/
- https://premom.com/
Is your product missing or out of date?
We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
Shihab Mia · Founder, Rankite
Shihab has spent more than a decade helping SaaS and e-commerce brands grow through search. He writes Rankite's software buying guides from pricing pages, documentation and public user reviews. More about Shihab.