Primrose
Privacy-centered, symptothermal fertility, pregnancy and menopause cycle tracking app.
- No ads, accounts or monthly subscriptions
- Optimized for symptothermal fertility awareness method
- Integrated location-based moon phase calendar
- All data stored privately on your device
- Modes for every era from maiden to matriarch
- Pregnancy mode that tracks symptoms and your baby's size week by week
- Custom tracking for weight, steps, or anything you want
Currently in beta and free to use. Available on Android only (for now).
Track Your Whole Cycle
Everything about your cycle, tracked in one clean calendar.
Cycle calendar
Your period, fertile window, and predicted ovulation at a glance.
Symptom logging
Flow, cramps, mood, energy, and sleep in a few taps.
Smart predictions
Forecasts that learn from your own cycle history.
Four modes
Switch between avoid, conceive, pregnancy, and peri/menopause.
Intimacy log
Record intimacy and contraception when you want, hidden when you do not.
How Primrose Compares to Other Period & Fertility Apps
A side-by-side look at pricing, privacy, data practices, and what each app actually tracks. Primrose is the only one combining on-device privacy, the symptothermal method, no subscription, and full life-stage tracking.
| App | Price | Legal / Regulatory History | AI | Sells / Shares Your Data | Ads | What It Tracks | Life Stages |
|---|---|---|---|---|---|---|---|
| Primrose | Free in beta; planned one-time fee later, never a subscription | None | No. Predictions run on-device from your own history | No. Stored only on your device, never uploaded, sold, or shared | No | Period, flow, cramps, mood, energy, sleep, BBT with coverline, cervical mucus, ovulation, intimacy, moon phases, custom metrics | Four modes: avoid pregnancy, conceive, pregnancy (week by week), peri/menopause |
| Flo | Free tier; Premium ~$50/yr | FTC settlement (2021) over sharing health data with Facebook and Google (FTC). A jury found Meta liable in 2025; Flo, Google, and Flurry settled for $59.5M (details) | Yes. AI assistant and insights | History of third-party sharing (settled). Cloud-based; says it no longer sells; added an Anonymous Mode | No in-app ads (subscription model) | Period, ovulation, 70+ symptoms, pregnancy, wellness | Cycle, conceive, pregnancy |
| Clue | Free tier; Clue Plus ~$40/yr | None known | Yes. Data-driven insights | Cloud-based (Germany, GDPR). States it never sells data, but data is stored on servers and could be subpoenaed | No in-app ads (subscription model) | 30+ metrics, period, ovulation, pregnancy, wearable integration | Cycle, conceive, pregnancy, perimenopause |
| Natural Cycles | Subscription ~$100–$150/yr, plus a thermometer | UK ASA banned its ad (2018) for misleadingly calling it "highly accurate"; Sweden's MPA reviewed it after 37 of 668 women reported unplanned pregnancies (report) | Yes. Proprietary algorithm (red/green days) | Cloud-based; uses data for research; not sold per its policy | No (subscription model) | BBT/temperature, fertile window, wearable temperature | Birth control, plan pregnancy, pregnancy/postpartum |
| Ovia | Free (consumer); Ovia+ via employer | No lawsuit, but criticized for sharing aggregated user data with employers and insurers (Washington Post, 2019) | Some personalized content and coaching | Yes. Owned by Labcorp; shares with employers, health plans, and ad partners | Yes. Personalized ad partners | Fertility, pregnancy, parenting, symptoms, coaching | Conceive, pregnancy, parenting (across separate apps) |
| Stardust | Free tier; paid subscription | No lawsuit, but its privacy policy once said it would share data with law enforcement "whether or not legally required" (removed after press), and it was caught sharing phone numbers with an analytics firm (TechCrunch) | Yes. AI plus astrology | Cloud-based; shared phone numbers with third-party analytics | Third-party trackers present | Period, symptoms, astrology and cosmic insights | Cycle (astrology focus) |
| Drip | Free (open source) | None | No | No. On-device, no trackers, open source | No | Bleeding, fertility (symptothermal: temperature + mucus), sex, mood, pain; graphs | Cycle and fertility awareness only (no pregnancy or menopause modes) |
| Euki | Free (nonprofit) | None | No | No. On-device, no back-end, no account | No | Period, symptoms, medication, sexual-health info; duress PIN | Cycle and sexual health only (no pregnancy or menopause modes) |
Pricing is approximate and changes; check each app for current rates. Legal and data-practice details reflect public reporting and regulatory records as of 2026, linked above. "Ads" refers to advertising shown inside the app; data shared for external ad targeting is noted separately under data practices.
A note from the maker
For years I moved from one period tracker to another, and each one let me down in some way. Some charged a monthly fee. Some sold my intimate data. Others were clumsy to use or missing the features I needed most. After waiting a long time for the market to offer something better, I stopped waiting and built it myself. I wanted an app with everything I had been looking for, one that never asks you to trade your privacy just to know when your period is coming.
Most cycle trackers are built around the rhythm method, which does not work well. The symptothermal method is different. Studies show that when it is used correctly, it is as effective as hormonal birth control. I wanted to make an evidence-based family planning option that women can trust, through every phase of life.
I built Primrose entirely on my own, and I could not be more excited to share it. It is free while it is in beta, and it will never carry a monthly subscription. After the beta I plan to offer it for a single, low, one-time fee, and I will always hold to one principle: your private health data belongs to you alone. Whatever your goals are, I hope Primrose can help. If you try it, please tell me what you think, good or bad.
With care,
Ivy
Maker of Primrose
Real Fertility Awareness
Primrose reads your body's real signs, not just a calendar.
Daily temperature
Log your morning temperature with an automatic coverline.
BBT charts
A clear chart for every cycle, with fertile days marked.
Confirmed ovulation
The temperature shift shows when ovulation has happened.
Export and share
Save any chart as an image to text or email your provider.
Knowledge base
Plain-language guides backed by primary research.
What to Look for in a Period Tracker
A good tracker should be accurate, simple, and honest about your privacy. Here is what actually matters.
- Real privacy. Your health data belongs on your phone, not on a company's servers.
- Accurate predictions. Clear forecasts for your period, fertile window, and ovulation day.
- Fast daily logging. Record flow, symptoms, and mood in a few taps.
- Support for any goal. Whether you are avoiding pregnancy, trying to conceive, pregnant, or navigating menopause.
- No ads or accounts. No sign-up, no email harvesting, no data sales.
- Charts you can share. Readable charts you can hand to a doctor or midwife.
Additional Features
Small touches that make daily tracking easier and more private.
- Moon phases. Integrated moon phase calendar calculated by zip code. Turn it off anytime.
- Gentle reminders. Optional alerts via push notification for your period, fertile window, and ovulation.
- Discrete notifications. Hide details from your lock screen notifications.
- You own your data. Export and import your full history whenever you like to back it up or share with providers.
- Circadian-friendly theme. A clean, modern interface with multiple color themes including one that limits blue light.
Frequently Asked Questions
Is Primrose period tracker app free?
Yes (for now). Primrose is completely free while it is in beta (for a limited time).
How is the symptothermal method different from the rhythm method?
The rhythm method, (AKA the calendar method), predicts your fertile days from the length of your past cycles. It assumes your cycles stay regular and does not look at what your body is doing right now, so an early or late ovulation can throw it off. The symptothermal method tracks real signs in your current cycle each day, mainly your basal body temperature and cervical mucus, to pinpoint the fertile window and confirm that ovulation has actually happened. Reading your real signs instead of a calendar average makes it far more reliable. In the largest prospective study of the method, couples who used it correctly had about a 0.4 percent yearly pregnancy rate, which is comparable to the hormonal contraceptive pill. You can read the study on PubMed.
Is my data private?
Yes. Your entries are stored on your device. They are not uploaded to a server, sold, or shared.
Do I need an account or internet connection?
No. There is no sign-up, and the app works offline.
Is Primrose available on iPhone?
Not yet. Primrose is available on Android only for now, but I am working on a version for IOS devices soon.
Can I use it for natural birth control?
Primrose supports the symptothermal fertility awareness method. Used correctly it is a recognized approach, though no method is perfect. It is recommended that you educate yourself on how to use this method correctly before relying on it as birth control.
Can I use Primrose while trying to conceive or pregnant?
Yes. Primrose has four modes, so you can switch between avoid pregnancy, conceive, pregnancy, and peri/menopause anytime for relevant tracking options to each stage of life.
How to Install Primrose on Android (APK)
Never installed an app this way before? It takes about a minute. Follow these steps on your Android phone.
- On your Android phone, tap the "Get Primrose on Android" button near the top of this page. The file will start downloading.
- When it finishes, tap the download, or open your Files or Downloads app and tap the Primrose file. Its name ends in .apk.
- Android may ask for permission the first time. Tap to allow installs from this source, then tap back.
- Tap Install and wait a few seconds.
- Tap Open. Primrose is ready to use.
You only need to allow this once. If you prefer, you can switch that permission back off afterward in your phone settings.
Leave Feedback or Report a Bug
Love it? Hate it? Something broken? Let me know about it using this form.