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Once -A special period tracker icon
GOOGLE PLAY

Once -A special period tracker

(주)넵튠 · Health & Fitness · United States store
NOT IN TOP 100 HERE
View on Google Play ↗ Instagram card
Revenue a month, worldwide
Too small to estimate
Not enough chart or ratings data
New ratings
Tracking
Daily counts start building from today
Rating
4.2 of 5
22.7K ratings in this store
Countries it ranks in
0
was 0 on Oct 16, 2026

Revenue

Estimated from the grossing charts of Oct 23, 2026 in the 53 countries we track.

EST. REVENUE / MONTH · WORLDWIDE
Unranked
Not in a grossing chart in any country we track, so there is no rank to estimate from. Most unranked apps earn far less than charted ones, often close to nothing.
LIFETIME INSTALLS (GOOGLE)
2.9M
About 15K per month on average since launch
RATINGS
22.7K
AVG RATING
4.15
PRICE
Free
IN APP PURCHASES
$0.99 - $8.49 per item
CONTAINS ADS
Yes
LAST UPDATE
81d ago
RELEASED
Jun 14, 2010
CONTENT RATING
Mature 17+

Last 30 days

From our daily snapshots of every grossing chart.

DAYS IN A GROSSING CHART
0 / 30
COUNTRIES NOW
0 (was 0)
EST. REVENUE FROM CHARTS, DAILY · GOOGLE PLAY ONLY EST
Show daily values
Sep 24, 2026not in a grossing chart
Sep 25, 2026not in a grossing chart
Sep 26, 2026not in a grossing chart
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Sep 28, 2026not in a grossing chart
Sep 29, 2026not in a grossing chart
Sep 30, 2026not in a grossing chart
Oct 1, 2026not in a grossing chart
Oct 2, 2026not in a grossing chart
Oct 3, 2026not in a grossing chart
Oct 4, 2026not in a grossing chart
Oct 5, 2026not in a grossing chart
Oct 6, 2026not in a grossing chart
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Oct 8, 2026not in a grossing chart
Oct 9, 2026not in a grossing chart
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Oct 11, 2026not in a grossing chart
Oct 12, 2026not in a grossing chart
Oct 13, 2026not in a grossing chart
Oct 14, 2026not in a grossing chart
Oct 15, 2026not in a grossing chart
Oct 16, 2026not in a grossing chart
Oct 17, 2026not in a grossing chart
Oct 18, 2026not in a grossing chart
Oct 19, 2026not in a grossing chart
Oct 20, 2026not in a grossing chart
Oct 21, 2026not in a grossing chart
Oct 22, 2026not in a grossing chart
Oct 23, 2026not in a grossing chart
Best rank Sep 24, 2026: not ranked. Now: not ranked. Days at zero are days outside every grossing chart.

Money and momentum

Measured from the store, not estimated.

WHAT IT CHARGES
$0.99 - $8.49 per item
Google Play only shows the price range per item.
REVIEW MOMENTUM
1.0 reviews / week
  • Trendfalling
  • Recent reviews average4.2 stars
  • Recent 1 and 2 star share13%
From the latest 500 written reviews, covering 3470 days. The store only returns this many, so this is the most recent slice.
RATING BREAKDOWN
22.7K ratings
5★67%
4★9%
3★7%
2★6%
1★11%

What users want

From the latest 500 reviews on the United States Google Play, Apr 23, 2017 to Sep 21, 2026: 13% are 1 or 2 stars. Open a theme to read what people wrote.

WHAT THEY COMPLAIN ABOUT · SHARE OF BAD REVIEWS
Login and account problems26%

17 of the 1 and 2 star reviews.

★★★★★ unfortunately I am not able to login from my registered email id.
★★★★★ I just upgraded my phone and I have at least 8 years of data gone because I can't log in to the app on my new phone.
★★★★★ Cannot login in or reset my password so all of my tracking is gone, or at least saved but I cannot access my profile/account.
Too many ads24%

16 of the 1 and 2 star reviews.

★★★★★ used to love it, but too many foreign ads, and it does not even open anymore.
★★★★★ Used to love this app, but when I switched phones I noticed it was showing a lot of non-English ads (possibly in Korean or Mandarin).
★★★★★ I can't read the privacy policy in english and the ads that keep popping up aren't in english....I can't read them..Please do something about it
Lost data, sync, backup15%

10 of the 1 and 2 star reviews.

★★★★★ Deleted it after 11 years today.
★★★★★ I just upgraded my phone and I have at least 8 years of data gone because I can't log in to the app on my new phone.
★★★★★ Cannot login in or reset my password so all of my tracking is gone, or at least saved but I cannot access my profile/account.
Bugs, things not working8%

5 of the 1 and 2 star reviews.

★★★★★ Plus, my brand new phone was acting oddly glitchy.
★★★★★ The app stopped working and years of data gone without a warning.
★★★★★ I think it may have a bug or something.
Wrong or poor results5%

3 of the 1 and 2 star reviews.

★★★★★ it's saying there is something wrong with the Facebook login.
★★★★★ Also, it's not accurate with my period!
Crashes and freezes3%

2 of the 1 and 2 star reviews.

★★★★★ Update (03.10.2019) it loads so slow and it crashes often...
★★★★★ I have always been using fb to login, and today when i need to check it out, the app just have to crashed!!!
Price and subscription3%

2 of the 1 and 2 star reviews.

★★★★★ But charging for an in-app purchase to remove ads for only 30 days, conveniently matching the length of a typical menstrual cycle, feels pretty degrading as a woman.
★★★★★ I can't get past ad since it is not in English and I refuse click on something that could scam me.
Worse after an update3%

2 of the 1 and 2 star reviews.

★★★★★ Update (03.10.2019) it loads so slow and it crashes often...
WHAT THEY ASK FOR
  • please make a list view eg January 01/01/2026. 4★, May 12, 2026
  • Try to add more features. 3★, May 8, 2023
  • i wish it had more things than just the pill taking method option. 5★, May 9, 2020
  • I just wish there were more features. 4★, Oct 26, 2019
  • uggh i love thid app, wish it had more symptoms and little things like that 5★, Jul 19, 2019
  • please include a section to dismiss the monthly cycle completely.... 5★, Jun 15, 2019
  • i just wish there werent so many overbearing ads. 4★, Mar 19, 2019
  • It would be awesome if I could toggle on/off if I want to see articles about pills and stuff or not. 4★, Feb 1, 2019
WORDS THAT KEEP COMING UP IN BAD REVIEWS
privacy policy4new phone5please help3won't let3
WHAT THEY LOVE · SHARE OF GOOD REVIEWS
Useful, it helps15%

61 of the 4 and 5 star reviews.

★★★★★ I think it would be a helpful option to add if you're pregnant, and to be able to add when you ovulated (based on blood test or LH) to make it more accurate.
★★★★★ I've been using it for a couple of yesrs and it helps me to track my period regularly.
★★★★★ It is a great app that is very helpful to know when your gonna have your period, the only problem that I find is it doesn't give multiple options of what birth control you are on
Easy to use14%

56 of the 4 and 5 star reviews.

★★★★★ And it's really simple to use.
★★★★★ Have been using this apps for few years have me keep track of my aunties visit me 😂 easy to use
★★★★★ It's so simple and I never lost my data for this 2 years.
Accurate, great results10%

40 of the 4 and 5 star reviews.

★★★★★ I think it would be a helpful option to add if you're pregnant, and to be able to add when you ovulated (based on blood test or LH) to make it more accurate.
★★★★★ Been using them for years now pretty accurate unless my cycle acting crazy
★★★★★ Love this app- super accurate and also includes relevant tips and advice :)
Looks great2%

9 of the 4 and 5 star reviews.

★★★★★ The interface it's beautiful and easy to use.
★★★★★ Perfect and so beautiful.
★★★★★ Beautiful UI, but I wish there were more symptom options or options to input your own.
Worth the money1%

3 of the 4 and 5 star reviews.

★★★★★ Love it and I thank the creators for the simplicity and the fact that it's free.
★★★★★ the only issue is the never ending ads but it makes it free to use so its all good.
★★★★★ Easy to use and i am worry free

Found by matching words and phrases in the reviews, not read by a person. A review can count toward more than one theme.

What users say

Latest reviews, United States Google Play.

★★★★★Sep 21, 2026

unexpectedly great. I have been using it for four years, never disappointed.

★★★★★May 28, 2026

unfortunately I am not able to login from my registered email id. It says there is no account associated with this. kindly help.

★★★★★May 15, 2026

Used this app for 11 years. Deleted it after 11 years today. Ads are annoying, sure. But charging for an in-app purchase to remove ads for only 30 days, conveniently matching the length of a typical menstrual cycle, feels pretty degrading as a woman. I understand ads needed to keep the app going but having to pay every 30 days and it not being a one off is poor. I've moved over to Flo and manually transferred my period data there.

★★★★★May 12, 2026

please make a list view eg January 01/01/2026. symptom - back ache 01/01/2026. symptom - food cravings 02/01/2026. symptom - cramps 02/01/2026. period starts - flow heavy 04/01/2026. symptom - severe cramps 06/01/2026. symptom - back ache 06/01/2026. period finishes February 03/02/2026. etc... just a list view allows you to see patterns of symptoms more easily and you can screenshot the list all in one go rather than having to click on each individual day one by one.

★★★★★Feb 9, 2026

my favorite app

★★★★★Aug 21, 2025

writing this review after using this app for 10 years. best thing ever. truly grateful to the whole team behind this.

Store screenshots

ScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshot

Growth research

Where this app is buying and earning its users. Each link opens pre filtered.

ASO keywords

Most repeated terms in the listing. Highlighted ones also appear in the title or short description.

menstrual19date15calendar10probability pregnancy10menstrual date10fertility8menstrual cycle8menstrual calendar8ovulation date8date fertility8ovulation7expected menstrual6external storage6women6probability6pregnancy6day6cycle5data5menstrual pain5contraceptive pill5high probability5ones uses5uses authority5

What's new in 5.5.1

No release notes.

Store description

For the all women who need menstruation recording calendar For the all women who need caring dairy for irregular menstrual pain and menstrual cycle For the all women who want to know the fertility, ovulation, contraception and probability of pregnancy through calendar For the all women who annoys marking menstruation and contraceptive pill on the calendar every time. For the all women who secretly record the symptoms of her body on the calendar. -- Must Have! Menstrual cycle management app, Once [ We fulfill the standard of menstrual cycle management app!] ** Menstrual calendar being more accurate as more as you use! It smartly calculate your menstrual cycle that was really hard to expect when the menstrual pain will come. In the menstrual calendar, you can see the expected menstrual date, ovulation day which has high probability of pregnancy, fertility and taking contraceptive pill at a glance, In the calendar history, you can see menstrual cycle at a glance. ** Taking care of ovulation date and fertility! You can easily recognize the ovulation date, fertility and expected menstrual date at a glance, so you can take care of yourself more preciously. ** Scientific calculation of probability of pregnancy! Based on the ovum survival period for 24 hours and the sperm survival period for 3 to 5 days, the 1 day before and after the ovulation date have high probability of pregnancy. We are displaying the probability of pregnancy as middle in the fertility period. ** The day that needs preparing of body and mind, prepare in advance! The day, for not to be embarrassed! In the needful situations(expected menstrual date/fertility with high probability of pregnancy / ovulation date etc when you want), they let you know the day in advance with alarm and sensible messages. ** Save my precious every day records simply! Save your data in more easier and simpler way than diary. If you sign up, you can store all the data that you record such as menstrual date, loving date, taking contraceptive pill, memo, auto calculated ovulation date and fertility period! Although you change your smartphone or install the app again after deleting, you can have data back in the menstrual calendar when you log in! ** Not only the menstrual date but also the secret love date! You can easily record the condition or symptoms of your body, the starting date of menstruation and menstrual pain. Once will be my secret diary that even can record the secret loving date! You don't have to worry about that someone will secretly look your diary because it has a lock function. ** Neat and refined design catching women's mind! 'The pretty app is good to see and also good to use' refined and neat design enhanced the usability of the menstrual calendar. By simple menstrual calendar, you can see the expected menstrual date and fertility at a glance. Like your cool diaries on your desk, Check cool designed calender application in your cell phone for your period. --- * Request permission WRITE_EXTERNAL_STORAGE ONES uses the authority of WRITE_EXTERNAL_STORAGE to save data READ_EXTERNAL_STORAGE ONES uses the authority of READ_EXTERNAL_STORAGE to load data GET_ACCOUNTS ONES uses the authority of GET_ACCOUNTS to improve its web environment. --- Let's be with Once that always does the best to offer the best service :D ※ You can get a fast response if you send the question to 'once@malang.kr' :) -- This service includes In-app Purchase items, and a separate fee will be charged for purchase. 

Terms of Service : https://bit.ly/38zBlvj
 Privacy Policy : https://bit.ly/3iqaZ3g

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