Once -A special period tracker
AD(x) Health & Fitness In-app purchases Contains ads
An app for girls surfing the crimson wave, once a month
- Rating
- 4.2
- 22.6K ratings
- Downloads
- 2.9M+
- on Google Play
- Price
- Free
- In-app purchases
- Updated
- Aug 3
- 2026 · v5.5.1
Screenshots
About Once -A special period tracker
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 '[email protected]' :)
--
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
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 '[email protected]' :)
--
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
User reviews
I've been using it for a couple of yesrs and it helps me to track my period regularly. Great app.
Been using this app for years.
best app .. using it for 3years
Great app. I've used it for years. It's helped me stay not pregnant, get pregnant and realize I was pregnant asap lol
Been using this for a year. Its simple 😌
Been using it since 2014. Best tracking period app ever. Love the tips! 👍
Alternatives to Once -A special period tracker
Looking for apps like Once -A special period tracker? Here are 6 similar Android apps on Google Play. The highest rated is Ladytimer Ovulation Calendar (4.8/5), and 4 of the 6 are free to download.
-
DaysyDay - Period Tracker 3.5
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Ladytimer Ovulation Calendar 4.8
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WomanLog Pro Calendar 4.7
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LADYTIMER Period Tracker 4.5
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Maya: Period Tracker for Women 4.7
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My Health And Period Tracker
| App | Rating | Price | Installs | Last updated | Compare |
|---|---|---|---|---|---|
| Once -A special period tracker | 4.2 / 5 | Free | 1,000,000+ | Aug 3, 2026 | |
| DaysyDay - Period Tracker | 3.5 / 5 | Free | 50,000+ | Aug 26, 2026 | Compare |
| Ladytimer Ovulation Calendar | 4.8 / 5 | Free | 5,000,000+ | Apr 27, 2026 | Compare |
| WomanLog Pro Calendar | 4.7 / 5 | 2.99 USD | 100,000+ | Oct 9, 2026 | Compare |
| LADYTIMER Period Tracker | 4.5 / 5 | 3.99 USD | 1,000+ | May 8, 2020 | Compare |
| Maya: Period Tracker for Women | 4.7 / 5 | Free | 10,000,000+ | Oct 10, 2026 | Compare |
| My Health And Period Tracker | – | Free | 5,000+ | Aug 30, 2022 | Compare |
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