All About Flo: A 2024 Review of the Period Tracker App

Flo is the most downloaded women’s health app. Here is an in-depth review of how Flo works and how it compares to other period tracking apps. Plus, a tester gives us an insider look.

Using a period tracker or fertility app can make charting your period, ovulation, or pregnancy pretty simple.

These apps help you track your symptoms, make predictions about your cycle, and show your cycle history and sexual activity, to name a few standard features. 

Flo does all of this and more. It’s currently the most popular period tracking app available, though it’s not without flaws and controversies.

Quick facts about Flo

• can be used to track periods, ovulation, pregnancy, symptoms, or more
• there’s a free version and a paid version
• you can do a free trial for the paid version
• you don’t have to answer all the onboarding questions

As with any app that asks for your personal health information, you should be informed about how it works before testing it out.

We do a full dive into Flo, including weaving some of our tester’s insight, to help you decide whether this period tracker app could help you better manage your reproductive health.

What is Flo period tracking app?

Flo is the most popular women’s health app. The London-based company was founded in 2015. According to Flo, the app boasts 380 million downloads and 68 million monthly active users. 

The app has both a free and paid version, offers a mode for pregnancy, the option to join and use anonymously, and a mode to share information with partners, plus many other features.

About our tester

Marie* tested Flo for 1 month, using the free version and then trying Flo’s free premium trial.

Marie took birth control pills for several years but made the switch to an IUD recently.

“I knew that this would probably throw off my cycle, change my symptoms, and more. I have always been very regular, but I knew during this transition I wanted to pay closer attention to the changes that came with switching my birth control method, so that I could better understand my new normal.”

Marie had used Flo before for about 2 years, but she stopped using it for some time before testing it for adoctor now.

*Name has been changed to respect our tester’s anonymity.

How does Flo period tracking work?

After downloading, most period tracking apps start the same way: asking you to enter some basic information. From there, you’re asked more reproduction-related questions, like when your last period was and how long your cycle usually is.

For any period tracking app to give you accurate information, like predicting your next period, you need to provide some details, though you usually have the option to skip certain questions.

Flo asks a significant number of questions after downloading, including your age or birth year (U.S. users must be at least 13 years old); your goals for using Flo; what type of birth control you use, if any (option to skip); and more.

Marie said setting up an account was “super simple” and that you could “really put as much or as little information in as you want.” She created a “simple profile” and noted that this app was really a “get out what you put in situation,” which makes this platform versatile for any kind of user.

Along with tracking periods, Marie said you can track your PMS symptoms (as many or as little as you have), and go back and add data, which Marie did often.

“All you have to do is click the day and click the button for a symptom or to check a box that you bled that day,” she said.

Flo also offers ovulation and fertility tracking, a feature Marie did not explore, as she was “not seeking to get pregnant at this time.”

She did say, though, that this feature seemed pretty unbiased, “in the sense that … it wasn’t geared specifically towards one goal, but rather adaptable to what I wanted.”

Overall, using Flo is simple: You enter the data you’re willing to share by logging your period start date on its calendar, adding any applicable symptoms, sexual and physical activity, mood, diet, information about your discharge, pregnancy tests and ovulation test results, and more if you’d like.

You can see your cycle information on the calendar whenever you open it, and can receive cycle reminders if you want them.

“After Flo has that data, it starts to calculate when you ovulate, and the more cycles you track, the more accurate it gets,” Marie said.

If you opt to receive push notifications from the app, you’ll see occasional messages from Flo related to your cycle, like “You may be experiencing breast tenderness today.”

Marie noted that the notifications were the only downside she found while using the app. Notifications are sent by default, so “if you want it to be more discreet, you would have to turn those off.”

Flo features

Flo is free to download. You can choose to either keep the free version or upgrade to its premium subscription, which offers more resources and ways to use the app.

Flo Free

This basic version gets you period and ovulation predictions, symptom tracking, cycle history, and anonymous mode. In addition to these resources, Flo has a desktop site where you can access a Health Library that discusses topics from pregnancy, general health, LGBTQ+ sexual and reproductive health, and more.

A unique feature that Flo has is a “secret” community chat center, which is an anonymous discussion forum.

Marie said the anonymous forum was “really unique because there aren’t a lot of organic safe spaces for menstruating folks to ask questions and share experiences in today’s day and age. I found this helpful for normalizing and validating some thoughts I had.”

Aside from these features, our tester shared that there are “soooo many educational resources in tons of different formats. There are articles, quick tips, FAQs, discussion forums, playlists, music … the list goes on and on.”

Marie liked that there was a variety of resources Flo offered, from super casual to super scientific. There are also some insights from medical experts, sex therapists, and discussions with other users that give the app a sense of community.

The feature Marie used most was the “Today” tab.

“There is a section on the ‘Today’ tab that gives quick resources based on where you are at in your cycle, and I used this section the most, as it was always the most relevant to me. I also really loved reading through some of the forums, especially around sex topics. It felt like a really safe space to learn and get advice,” she said.

Flo Premium

Paying for the app unlocks access to everything the free version has plus much more.

One example is Flo’s virtual health assistant. The company describes this chatbot as an “interactive dialog tool” that provides an extensive cycle report, among other information like signs of disorders, including polycystic ovary syndrome (PCOS), and endometriosis.

Flo says the feedback from this feature is based on the latest medical evidence and checked by at least two medical specialists.

Premium also offers more detailed pregnancy tracking, symptom tracking and predictions, daily health insight stories, video courses, and more.

Pregnancy mode

Flo is just one single app, so if you want to use it for pregnancy, you need to select that option upon downloading it or change your goal from period tracking to pregnancy, which switches you over to pregnancy mode.

If you pay for Premium, you’ll get more detailed pregnancy tracking than the free version.

If you’re trying to conceive, you can select that as your goal as well. Note that you can chart the end of a pregnancy via delivery. Flo’s website says you can also log a miscarriage or abortion starting on day 29 of pregnancy.

Flo for Partners

Paying for the app unlocks the option to link your information over to your partner. This gives them access to view information like which day of your cycle you’re on, your possible period symptoms, chance of pregnancy, and more.

Your partner can also choose to receive notifications from the app and get access to Flo’s articles and videos.

How much does Flo cost?

Flo is free to use and download. However, there is a paid subscription option Flo Premium.

Flo Premium generally costs $39.99 per year or $11.49 per month. You can usually find promotional pricing available for discounts.

For example, you can enable a free trial of Flo Premium in the app by clicking on any of its locked features, like its educational articles and videos.

You’ll also see promotional offers in the app, like $7.99 for 1 month. You may also catch discounts via push notifications and emails.

Who can use it?

Flo can be beneficial for many different types of users, from anyone who wants to track menstrual and PMS symptoms to people who want help to make sure they don’t get pregnant.

Marie could see anyone who menstruates benefitting from this app.

“It is good for the simple user who just wants to know when they are ovulating and when to expect their next period. It is also good for the user who might want to get really granular about understanding PMS symptom patterns, learn about reproductive and sexual health, chat with others anonymously about casual or serious health topics, and more.

“This app is really a get out what you put in situation, so I think that versatility lends itself well to any kind of user,” Marie said.

Limitations of Flo and other period tracking apps

Period tracking apps like Flo are not a form of birth control.

While these apps can provide helpful information about your cycle, including your fertility window, they do not offer protection from pregnancy, nor do they protect you from sexually transmitted infections (STIs).

Instead, period tracking apps are best used as a digital tool for keeping track of your sexual activity and symptoms.

Additionally, for period tracking apps like Flo to deliver accurate information, you have to use them consistently. Forgetting to enter certain data, like when your period came or when you had unprotected sex, may result in misguided information from the app.

How Flo compares to its competitors

Flo may be the most popular period tracking app, but it’s far from the only one.

A 2023 study analyzed 34 period tracking apps, including Flo. Researchers found that 31 of the apps could be used to predict the menstrual cycle. Results also showed that Flo ranked in the top five apps in the study, which was based on consumer scoring.

Other apps offer many similar features to Flo at no cost.

For example, an app called Ovia tracks fertility, pregnancy, and periods, and offers completely free health tips and articles.

It seems Flo allows free access to its health library on its website — not its app — without needing to pay for its premium subscription, however. The website also offers calculators for ovulation, pregnancy, IVF, and more.

Keep in mind each company has its own privacy policies. It’s best to review them carefully before downloading.

	Cost	iPhone and Android rating	Pregnancy tracking	Data deletion available	Learning resources
Flo Period & Pregnancy Tracker	• $39.99 per year • $11.49 per month • discounts and free trials available	• iPhone rating: 4.8 stars • Android rating: 4.7 stars	yes	yes	with paid subscription only
Clue Period & Cycle Tracker	• $39.99 per year • $9.99 for 1 month	• iPhone rating: 4.8 stars • Android rating: 4.3 stars	yes	yes	with paid subscription only
Ovia: Fertility, Cycle, Health	free	• iPhone rating: 4.8 stars • Android rating: 4.5 stars	separate Ovia app for pregnancy tracking	yes	yes, free
Spot On Period Tracker	free	• iPhone rating: 4.3 stars • Android rating: 3.9 stars	no	yes	available for free via Planned Parenthood websites

Pros and cons of Flo Period Tracker

Pros

• most popular women’s health app
• many users find it reliable and easy to use
• free version available for basic period, ovulation, and pregnancy tracking
• can be used to help conceive or avoid pregnancy
• premium version offers many extra features, like extensive cycle reports, detailed pregnancy tracking, partner sharing feature, educational resources, and more
• can set reminders for taking birth control
• discount offers and free trial for the premium version are generally easy to find

Cons

• the free version gives frequent reminders about the paid subscription option, making clicking around on the free version a bit tedious
• like other period apps, Flo has a recent history of controversy around privacy
• Flo asks many questions upon downloading it, though you can skip almost all of them if you prefer
• users must be at least 13 years old to use in the United States, and at least 16 years old to use in the European Union, United Kingdom, and Canada

Period tracking apps and privacy

Data storage and privacy concerns are common roadblocks for many people considering period tracking apps.

The overturn of Roe v. Wade in 2022 led many people to delete their data and uninstall their period tracking apps for fear of their information being sold.

While data sharing is not uncommon for apps of all kinds, the fear around data sharing and period apps specifically is the potential for that information to be subpoenaed for suspected abortions in states where it’s illegal or highly restricted.

In response to the overturn of Roe v. Wade, Flo rolled out a feature for both the free and paid versions of the app called Anonymous Mode.

This mode allows users to enter their data without identifying details like their name, email address, and more.

How does Flo handle privacy?

In 2021, Flo reached a settlement with the Federal Trade Commission (FTC) that it discloses briefly on its website.

According to the statement, between June 30, 2016, and February 23, 2019, Flo sent an identifying number related to its users and information about their periods and pregnancies to companies that assist Flo with measuring and analyzing trends, usage, and activities on the app, including the analytics divisions of Facebook, Flurry, Fabric, and Google.

It goes on to say that no information was shared with the social media divisions of these companies.

“We did not share your name, address, or birthday with anyone at any time,” Flo stated.

In a statement to Healthline, the company emphasizes that its agreement with the FTC was in no way an admission of any wrongdoing, adding it has a strict set of policies and procedures to safeguard user data.

For example, the company also partnered with Cloudfare in an effort to protect user data with its Anonymous Mode accounts.

Flo lists its ISO certifications and privacy policies and technologies on its website.

Remember: You don’t NEED a period tracking app

You don’t have to use an app for period tracking. You can simply log your cycle information in a physical period tracking journal, many of which you can find at budget-friendly prices via Amazon.

Flo reputation and reviews

Aside from the FTC settlement in 2021, which stirred up controversy, Flo has an overall strong reputation among its millions of users.

iPhone users currently rate it 4.8 out of 5 stars, and Android users give it 4.7 stars.

Many users love the app, saying it helps them keep track of periods and pregnancy, but many complain that it doesn’t include as many free features as it used to.

Notably, many reviewers say the app displays several pop-up prompts asking you to subscribe to the premium version, which many find frustrating to work around.

The company is not currently accredited by the Better Business Bureau (BBB), and its BBB rating is an F.

Our tester’s takeaway

Marie decided she will keep using the app after her free trial of Flo Premium ends.

“I liked having the reminder of when to expect my next period, and when my chances of getting pregnant were higher,” she said.

But more than that, Marie found the app has really helped her see “how connected my emotions and moods are with the different phases of my cycle.”

She also shared that she lives with “anxiety and OCD, and found that I was better able to attribute what would previously be confusing emotions to now a more clear hormonal shift. It really helped me to understand myself better and put less blame on myself to find root causes for sometimes confusing waves of emotions.”

“Flo has also taught me a lot about my ovulation. Since I am on birth control for preventing pregnancy, and the IUD is extremely effective, I haven’t been too concerned with my days of highest fertility, but I could see how someone using other birth control methods would find this super helpful,” she said.

Frequently asked questions about Flo

Is the Flo app accurate for periods?

Yes, Flo is praised by many users for its period tracking accuracy.

Is Flo not free anymore?

Flo is still available for free. The paid subscription offers more extensive features, such as personalized cycle reports, partner sharing, detailed pregnancy tracking, and more.

How much is the Flo app a month?

The app is free, but its premium version costs $39.99 per year or $11.49 per month. You can usually find a promotional offer via push notifications, emails, or directly in the app. The app also allows users to enable a free trial of the premium version.

Is Flo a good pregnancy app?

Flo is the most popular period tracking app, as it is the most downloaded. Many users set their mode to pregnancy for simple tracking or upgrade to the premium version for access to detailed pregnancy tracking.

Takeaway

Flo is a free period tracking app that allows you to keep track of your cycle and much more.

It’s one of the most popular apps of its kind. Many rely on it for accurate predictions and help managing their reproductive health.

The premium version has a slew of extra resources and more ways to use the app, but it does cost around $40 per year or $11.49 per month, though you may find a promotional offer for a lower monthly rate.

Period tracking apps like Flo ask for your personal information, which you may or may not feel comfortable sharing.

Staying informed about how your data is used and stored can offer peace of mind. If you’d rather keep your information totally secure, you can always opt for a physical period tracking journal instead.