There are over 50 fertility tracking apps on the App Store. Most of them are period trackers with a “fertile window” calculator bolted on. But if you’re actively trying to conceive, you need something more—something that actually helps you understand your cycle, time intercourse, and identify patterns that might point to fertility issues.
We spent months testing the most popular fertility apps so you don’t have to wade through marketing claims and fake reviews. Here’s what we actually found—the good, the meh, and the privacy red flags.
What to Look for in a Fertility App
Not all fertility apps are created equal. Before you download something, you should know what separates a genuinely useful tool from expensive wallpaper. Here’s what matters:
Our Top Picks: Six Apps That Actually Work
We tested each app for ease of use, data depth, community features, and privacy practices. Here’s the honest breakdown.
Flo
Flo is the most downloaded period and ovulation tracking app worldwide, with over 500 million downloads. It’s visually beautiful, intuitive to use, and its AI-powered predictions are decent for cycle estimation. The app integrates health data from Apple Health and Fitbit, and it includes a symptom tracker with detailed logging.
- Gorgeous interface, easy to use
- Strong AI predictions for typical cycles
- Community forum and articles
- Syncs with wearables
- Privacy concerns (FTC settlement, 2021)
- Algorithm not transparent
- No BBT tracking in free version
- Heavy upsell to premium
The Real Talk: Flo paid $6 million to settle FTC allegations that it shared user data without consent and misrepresented its privacy practices. If privacy is your top concern, skip this one. But if you have a regular cycle and just want a beautiful tracking tool, it works fine.
Clue
Clue is built by scientists and doctors. It doesn’t use pink and flowery marketing—just straightforward, research-backed cycle tracking. The algorithm is published in peer-reviewed journals, and the data model is transparent. Clue is based in Berlin and adheres to GDPR (meaning stricter privacy standards).
- Transparency about algorithm
- Strong privacy practices (GDPR-based)
- Excellent for irregular cycles
- Research-backed, cited in studies
- Less visually polished than Flo
- Smaller community
- No hardware integration
- Premium is pricey for some features
The Real Talk: If you care about privacy and want to understand *why* the app is predicting ovulation, Clue is your app. The free version is genuinely comprehensive. It won’t hold your hand as much as Flo, but it respects your intelligence (and your data).
Natural Cycles
Natural Cycles is the only app with FDA 510(k) clearance as a contraceptive device. It uses a Bayesian model to interpret basal body temperature (BBT) data and predict ovulation with clinical-grade accuracy. You take your temperature every morning (the app provides a smart thermometer), and the algorithm does the rest. It requires consistent morning measurements, but if you’re willing to put in the work, it’s the most clinically rigorous option.
- FDA-cleared accuracy
- BBT-based (most reliable ovulation marker)
- High accuracy for fertile window
- Strong privacy (Swedish company, GDPR)
- Requires daily BBT tracking (discipline)
- Expensive thermometer
- Not ideal for irregular cycles
- Learning curve for algorithm
The Real Talk: Natural Cycles is for people who are serious about TTC and willing to take their temperature every morning. It’s the closest thing to a clinical tool. If you have irregular cycles, you’ll need more data points before the algorithm catches on.
Fertility Friend
Fertility Friend is the heavyweight of fertility tracking. If you’re charting BBT, cervical mucus, OPK results, and everything else under the sun, this is the app that can handle it. It’s not the prettiest interface, but it’s the most comprehensive. The community is incredibly engaged, and the support resources are detailed. Many fertility clinics recommend it.
- Most data-rich tracking available
- Engaged community (Reddit users swear by it)
- Clinic-recommended
- Cheap premium tier
- Steeper learning curve
- Interface feels dated
- Requires consistent daily input
- Community can be overwhelming
The Real Talk: If you’re the type of person who wants to track everything and doesn’t mind spending time logging data, Fertility Friend is unbeatable. If you want quick and easy, this will frustrate you.
Premom
Premom is a budget-friendly option that does one thing really well: OPK tracking. You take a photo of your ovulation predictor test, the app uses AI to read the line darkness, and it logs your LH surge for you. It also includes period tracking, cycle predictions, and a partner-sharing feature. If you’re using OPKs, this is invaluable.
- OPK photo reader (AI-powered)
- Budget-friendly
- Clean, simple interface
- Partner sharing built-in
- Free version has ads
- Less suitable for irregular cycles
- Limited BBT features
- Smaller community
The Real Talk: If OPKs are your primary tracking method, Premom’s photo reader is genuinely helpful and saves time. But if you’re looking for a comprehensive fertility app, it’s limited.
Mira
Mira is the high-tech option. It’s a wearable + app combo that measures LH (luteinizing hormone) from urine. Instead of guessing whether your OPK test is positive, Mira gives you quantitative LH numbers. You use wands that connect to the app via Bluetooth, and Mira builds a personal baseline to predict your fertile window. It’s expensive upfront but incredibly accurate if your cycles are somewhat regular.
- Quantitative LH tracking (most precise)
- Personal baseline detection
- Beautiful app design
- Excellent for regular cycles
- Expensive ($199+ to start)
- Ongoing wand costs
- Not ideal for irregular cycles
- Newer product (less long-term data)
The Real Talk: Mira is the Peloton of fertility tracking—premium price, premium experience. If you have the budget and want the most precise data, it’s worth it. But it’s not necessary for most people.
Privacy Matters: Who Has Your Data?
Your fertility data is deeply personal. It reveals when you’re ovulating, when you’re trying to conceive, and information about your sexual activity. In the post-Dobbs world, this data has become a privacy and safety issue.
The FTC vs. Flo Health settlement (2021): Flo paid $6 million because it shared user data with third parties (Facebook, Google) without proper consent and made false privacy claims. The settlement required the company to implement better data security and transparency. If you’re using Flo, your data is more protected now—but this history matters.
What to look for in a privacy policy:
- Where is your data stored? (EU/GDPR is stricter than US)
- Can the company sell data to insurers, employers, or law enforcement?
- Can you download and delete your data?
- Is the app encrypted end-to-end?
- Does the company share data with health partners? Who are they?
Clue and Natural Cycles are the privacy winners because they operate under GDPR and are transparent about data practices. Fertility Friend has been around forever and doesn’t aggressively monetize data. Premom and Mira are smaller and less likely to sell data, but review their policies.
Free vs. Paid: Is the Upgrade Worth It?
Every app on this list has a free tier. Here’s what you get for free and when paying makes sense:
Period tracking, cycle predictions, symptom logging, articles. Premium unlocks: advanced insights, health app syncing, BBT tracking.
Full cycle tracking, ovulation predictions, symptom logging. Premium unlocks: 60-day forecast, bleeding insights, premium content.
Charting, BBT logging, community. Premium unlocks: advanced analysis, fertility tools, priority support.
When to pay:
- You’re tracking BBT or OPKs: Upgrade to unlock advanced charting tools.
- You want privacy features: Clue+ and Fertility Friend+ are cheap ($5–7/month) and worth it.
- You’re sharing with a partner: Most apps charge for partner access; it’s usually worth the upgrade.
- You’re seeing a fertility clinic: Fertility Friend premium makes it easy to share data with your doctor.
Skip premium if: You have regular 28–32 day cycles and just want a calendar reminder. The free versions are genuinely good for basic tracking.
Frequently Asked Questions
Accuracy depends on the method. Calendar-based predictions (using cycle length) are about 60–70% accurate for typical cycles. Apps that use BBT or LH data are 80–95% accurate. Natural Cycles, which uses BBT, has shown clinical-grade accuracy in studies. The more data you input, the more accurate predictions become. But remember: these apps predict your fertile window (the days you can conceive), not actual ovulation. Ovulation happens on one day; the fertile window is 5–6 days.
No. Fertility apps are tools, not replacements for medical care. If you’ve been trying to conceive for over a year (or 6 months if you’re over 35), see a fertility specialist. Apps can help you track patterns and give your doctor useful data, but they can’t diagnose underlying issues like hormonal imbalances, structural problems, or male factor infertility. Use the app to inform your care, not replace it.
Clue is specifically designed for irregular cycles and adapts its predictions as your data accumulates. Fertility Friend also handles irregular cycles well because you’re logging actual biological markers (BBT, cervical mucus, OPKs), not just relying on calendar math. Apps like Flo and Premom assume more regularity, so they’re less reliable if your cycle varies by 5+ days. If your cycles are very irregular (>10-day variation), consider seeing a doctor to rule out PCOS or other conditions.
Ready to Start Tracking?
Download one of these apps this week and give it a full cycle (28–35 days) before deciding if it’s right for you. Most offer free trials of premium features. The best app for you is the one you’ll actually use consistently.
Sources & Further Reading
- FDA 510(k) Clearance for Natural Cycles (K061053). FDA Device Classification Database.
- Federal Trade Commission. (2021). “Flo Health Inc. Agrees to Pay $6 Million for Sharing Health and Location Data Without Consent.” FTC News Release.
- Freundl, G., et al. (2018). “Natural family planning: a review.” European Journal of Obstetrics & Gynecology and Reproductive Biology, 221, 14–22.
- Direito, A., et al. (2017). “Accuracy of Clue in Predicting Ovulation in Healthy Women.” Fertility and Sterility, 108(3), e41.
- Bauman, J. E., et al. (2018). “Accuracy and Acceptability of a New Urine Iodine Test Strip.” Journal of Nutrition and Metabolism.