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Updated July 2026 · real, multi-region App Store reviews
Head-to-head

Clue Period & Cycle Tracker vs Flo Cycle & Period Tracker

Clue Period & Cycle Tracker 4.8★ · Free + IAP 75
Winner Clue Period & Cycle Tracker
Flo Cycle & Period Tracker 4.7★ · Free + IAP 70

Both Clue and Flo are highly-rated period trackers, but Clue has a slight edge for users who prioritize a less intrusive free experience, while Flo offers more comprehensive features for paying subscribers.

Full reviews: Clue Period & Cycle Tracker · Flo Cycle & Period Tracker

Clue and Flo are popular period tracking apps with similar lifetime ratings. Both offer free versions but heavily push paid subscriptions. Clue is praised for its ease of use and accuracy, though recent reviews criticize its aggressive subscription pop-ups. Flo is also accurate and feature-rich for paid users, but its free version is perceived as very limited and its subscription price is a common complaint.

Head to head

Features edge: Flo Cycle & Period TrackerR5R12R23R32
Clue Period & Cycle Tracker Clue is appreciated for its comprehensive tracking options for symptoms and daily activities, with many users finding the free version sufficient for basic tracking R5R32R23. However, some paid users desire more specific tracking options, such as for IUDs or certain exercise types R12.
Flo Cycle & Period Tracker Flo offers extensive features, including pregnancy tracking, anonymous posts, and advice, especially for premium users . However, many advanced features and insights are locked behind a paywall, leading to frustration among free users .
Ease of Use tieR1R3R4R5
Clue Period & Cycle Tracker Clue is consistently described as easy to navigate and simple to use, even for new users R5. However, the constant pop-ups for subscriptions significantly detract from the user experience, making quick entries take longer R1R3R4.
Flo Cycle & Period Tracker Flo is generally considered intuitive and well-designed with a clean interface . Similar to Clue, users report that the frequent subscription prompts hinder the ease of use .
Reliability edge: Clue Period & Cycle TrackerR2R5R14R35
Clue Period & Cycle Tracker Clue is praised for its accuracy in predicting periods, with predictions improving over longer-term use R2R5R14R41. Users appreciate its ability to predict mood swings and other symptoms accurately R35R38.
Flo Cycle & Period Tracker Flo is also noted for its accuracy in predicting cycles and helping with fertility planning . However, some users report that it has failed to predict their period dates correctly, even with consistent symptom logging .
Price/Value edge: Clue Period & Cycle TrackerR1R4R6R8
Clue Period & Cycle Tracker Clue offers a free version that many users find sufficient for basic tracking, and its paid version is considered affordable by some R8R32. However, recent reviews heavily criticize the constant, intrusive pop-ups and full-screen ads pushing the paid subscription, making the free experience frustrating R1R4R6. Some feel the free version has become very limited .
Flo Cycle & Period Tracker Flo's free version is widely perceived as very limited, with most valuable insights and features locked behind a premium subscription . Users express frustration over the high subscription price, with some noting a significant increase over time . There are also reports of unexpected charges and difficulty with refunds R85.
Support tieR22R82R85
Clue Period & Cycle Tracker One user reported issues with incorrect charges for a subscription and received no helpful response beyond a chatbot or AI assistant R22.
Flo Cycle & Period Tracker One user reported being charged for a subscription after canceling and deleting the app, and did not receive a refund despite emailing with proof R85. Another user reported issues with an annual membership and changes to the app's functionality after it expired, with no clear resolution R82.
Pick Clue Period & Cycle Tracker if

You want a reliable, easy-to-use period tracker with a functional free tier for basic tracking and value data privacy R2R5R8R32. You are willing to tolerate frequent, but dismissible, pop-ups for the paid subscription R3.

Pick Flo Cycle & Period Tracker if

You are looking for a comprehensive period and fertility tracker with extensive features, and are willing to pay for a premium subscription to access them . You appreciate community features and detailed insights into womanhood .

Evidence note: Both apps have a significant number of recent negative reviews primarily focused on aggressive subscription prompts and perceived limitations of the free versions. This skews recent sentiment compared to their high lifetime ratings. The free-vs-paid asymmetry is very apparent, as many negative reviews come from users frustrated with free-tier limitations or constant upsells.

Frequently asked

Are Clue and Flo really free?
Both Clue and Flo offer free versions, but users report that the free experience is increasingly limited and frequently interrupted by pop-ups and full-screen ads pushing paid subscriptions R1R4R6. Many advanced features, insights, and educational content are locked behind a paywall in both apps R18.
Which app is more accurate for period prediction?
Clue is widely praised for its accuracy, with many long-term users reporting that its predictions improve over time and are often spot-on for period arrival and symptom prediction R2R5R38R41. Flo is also considered accurate by many users, especially for fertility and pregnancy planning, but some reviews indicate it can be off on period dates even with consistent logging .
Do these apps sell user data?
One Flo user expressed concern about the app being part of a lawsuit that sold user information, though they noted that privacy might not matter given government surveillance R90. Another Flo user explicitly stated that Flo reports data to the government and switched to Clue for privacy reasons R97. Clue, on the other hand, is appreciated by a user for its commitment to keeping data private R8.

What reviewers actually said

Built only from these 120 real reviews (foreign ones translated). Superscripts jump to the quote here. Apple has no per-review links, so [ref] opens that app's reviews on the App Store.

  1. [R5] Clue Period & Cycle Tracker 5/5 · US I had this app for 5 years you won’t regret it: To start off I first got this app in 8th grade, I’m now a rising freshman in college and I absolutely LOVE this app, it’s so easy to navigate and navigate. There are option for every symptom or daily activity. I love how clear it is, as someone who has had irregular period for the last 3 years, this app never failed to at least be close to the predic
  2. [R12] Clue Period & Cycle Tracker 3/5 · US Lackluster IUD Tracking: I have a paid subscription for Clue and use the Clue Tracking mode without a period because I don’t bleed so the Period Tracking mode doesn’t really work for me. Unfortunately, that means the Clue Connect and widget features are completely unavailable to me. As a paid user, I’d love to see features that support IUD users because even though I don’t bleed, I do have period
  3. [R23] Clue Period & Cycle Tracker 5/5 · US Amazing: This app is so good that I can also track my emotions
  4. [R32] Clue Period & Cycle Tracker 5/5 · US Good app for period tracking: Overall, this is a good app. It has enough features without paying anything, it doesn’t have ads (it asks you if you want to subscribe when you open the app or if you click on a feature that needs a subscription but you can easily close it), and it has more features than Apple Health’s cycle tracking. Features that would be very useful if they were added: - Being abl
  5. [R1] Clue Period & Cycle Tracker 1/5 · US gone downhill: the app CONSTANTLY has pop-up screens trying to force you to buy a paid subscription. it’s infuriating to open an app for what should be a 30 second entry and have it take more than twice as long due these greedy tactics.
  6. [R3] Clue Period & Cycle Tracker 3/5 · US 5 stars until: this app is hands down easy TEN STARS but every.damn.time. i open the app i get a promo. that's nice and everything but it should only pop up once a week if you open the app frequently bc it's literally just too much. tapping out of several pop up ads for premium before i can look at my data, several times a day if i'm logging or checking during curtain windows is too excessive. tru
  7. [R4] Clue Period & Cycle Tracker 1/5 · US Ads to upgrade: Super annoying to get an ad pop up every second of using the app, an ad to upgrade to premium. Extremely excessive
  8. [R2] Clue Period & Cycle Tracker 5/5 · US So good and reliable: I have been using this app since I was 17 years old and now I am 25. It is really helpful.
  9. [R14] Clue Period & Cycle Tracker 5/5 · US Clue: This app has been so so helpful in tracking my period! It helps me to plan ahead of time!
  10. [R35] Clue Period & Cycle Tracker 5/5 · US Love it!: I have been using this app for years, even after having a hysterectomy. My hormones are so bad, that I use it to track the monthly changes and my luteal phase so I know when I’m not just being crazy and know when to expect the intense and sudden onset of my PMDD. Thank you!
  11. [R6] Clue Period & Cycle Tracker 3/5 · US Helpful but frustrating: The tracking is very helpful in this app, however the constant pop ups for “90 percent off” are pretty annoying. If you’re not paying for the subscription the adds are incessant and it makes it more difficult to use the basic features.
  12. [R8] Clue Period & Cycle Tracker 5/5 · US Affordable app with data privacy: I appreciate that Clue offers insight and articles for you to read and is very affordable when it comes to the paid version. But you still have a free version too! Plus the fact that they’re committed to keeping your data private.
  13. [R22] Clue Period & Cycle Tracker 1/5 · US Wrong Charges: They offered me 3usd clue plus and when I paid they charged me 43.99usd! No answer back. Only chatbot and a AI assistant which leads a “we didn’t find any purchase with your info” but definitely on my card is the charge.
  14. [R82] Flo Cycle & Period Tracker 1/5 · US Pésimo servicio de un año acá: Tengo más de 10 años que la usaba ya dejaré de hacerlo porque pagué todo un año de membresía y ya después que se cumplió no pude volver a pagar y la aplicación cambió por completo porque antes daban consejos y se agregaba síntomas y en base a eso siempre había cosas que leer y ahora todo me sale en blanco ni me avisa ni nada y todo eso lo hacía antes de yo pagar y pa
  15. [R85] Flo Cycle & Period Tracker 1/5 · US Do not download: charged my card 60 dollars even tho i had cancelled and deleted the app i have emailed asking for a refund with screenshots of my proof and they didnt reply back. I would not recommend this app
  16. [R18] Clue Period & Cycle Tracker 3/5 · US Disappointed: I love how there’s so much more to track instead of how simple the app in Apple is. However, I was a bit bummed that in order to access more data & tracking, we have to pay a subscription. It’s not expensive, it’s not that. It’s that it’s one more thing we have to pay for in order to track our health. We already have pay for our period every month between tampons, pads, pain manageme
  17. [R38] Clue Period & Cycle Tracker 5/5 · US Best app, Don’t have to think about anything just open & know: Clue has somehow become the FBI agent assigned to my uterus. Me: “Why am I crying because my avocado was too ripe?” Clue: “Give it 48 hours.” …and then 48 hours later, there it is. Every. Single. Time. It predicts my mood swings better than I do, reminds me why I suddenly want chocolate and a nap, and saves my family from wondering
  18. [R41] Clue Period & Cycle Tracker 5/5 · US Accuracy improves with longer term use: I’ve had this app since 2017, for period tracking only (not for pregnancy) and have been a subscriber since 2022. This is the only app I’ve ever used and it stuck with me for a reason. The predictions get better the longer you log ur data. Sometimes it lets me know I’m getting my period on a given day and it can be spot on at times for me. Overall, this app
  19. [R90] Flo Cycle & Period Tracker 3/5 · US Expensive, but helpful: I enjoy this app. I pay for it to track my cycle. Concerns/Areas to improve: 1. I’m worried they are apart of the lawsuit that sold our information, but I guess since the government watches us anyway, it doesn’t matter. 2. It would be great if the notifications could be adjusted. 4-5 notifications with irrelevant things isn’t helpful, perhaps letting us adjust the settin
  20. [R97] Flo Cycle & Period Tracker 2/5 · US There are better options: Flo reports your data to the government and I’m not a huge fan of that. Women should have privacy regardless. Also, you have to pay if you want to access your cycle trends, which is outrageous. The only thing that is free is the private chatrooms and inserting your period updates. I switched over to Clue where I don’t have to for anything if I don’t want to and I can stil

Synthesized from 120 recent App Store reviews · updated July 2026 · View on the App Store