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Soso vs. Period Calendar

Soso has no ads and no intimacy log. Period Calendar has both.

Soso is made for a girl getting ready for her first period, with no ads and no adult features. Period Calendar is one of the most downloaded period trackers, with more than 100 million installs on Google Play, and it is not made for younger girls: it contains ads, logs intimacy and fertility, is rated 13+ on the App Store, and its privacy policy says it does not address anyone under 13.

Reviewed Oct 8, 2026

Soso is best for

A girl getting ready for her first period, or in her first years of cycles, in an app with no ads and no adult features.

Period Calendar is best for

Adults who want a long list of tracking categories, ovulation and pregnancy tracking, several profiles on one phone and Wear OS, and who do not mind ads.

Our verdict

For a girl getting ready for her first period, choose Soso: no ads, no intimacy log, and an experience made for her age that starts before her period does. Period Calendar is a capable tracker for adults.

Side-by-side comparison

The criteria that matter most for early cycles.

Made for
Soso:Tweens before and after their first period, and their parents. Rated 9+ on the App Store.
Period Calendar:Rated 13+ on the App Store. Its privacy policy says the service does not address anyone under 13.
Before the first period
Soso:A whole experience for girls who have not had their first period yet. She gets an estimate of when it may arrive, and the window narrows as she logs the signs of puberty. It is an estimate, not a date: a first period can come earlier or later.
Period Calendar:Period Calendar’s predictions come from periods already logged. It has no estimate of a first period.
Puberty body changes
Soso:She follows her breast and pubic hair development by picking, in private, the closest of a set of illustrated stages, and logs her height each month.
Period Calendar:No puberty stages. It records height and weight for BMI.
Privacy
Soso:App Store label: no data used to track her and nothing linked to her identity. Her cycle data is never sent to Soso’s servers.
Period Calendar:App Store label (iOS version): identifiers and usage data may be used to track you, and health data is linked to your identity.
Account and backup
Soso:No account to create. Optional backup and sync between her devices through your own iCloud or Google Drive, never through Soso’s servers.
Period Calendar:No account needed, a real strength. Backup and sync are available.
Ads inside the app
Soso:No ads.
Period Calendar:Contains ads.
Intimacy, fertility and pregnancy
Soso:None. No intimacy log, no fertility window, no pregnancy mode.
Period Calendar:Logs intimacy, ovulation and fertility, with pregnancy tracking.
Cycle tracking
Soso:Period, flow, spotting, discharge, mood and symptoms, in a calendar made for the first cycles.
Period Calendar:Periods, flow, moods, symptoms, ovulation and much more.
Devices
Soso:iPhone, iPad, Android and Apple Watch, with Siri.
Period Calendar:Android and iPhone, with Wear OS.
Learning
Soso:Puberty and first periods explained for her age, with a quiz a day. The sources behind our health information are public on our Medical Sources page.
Period Calendar:Built around tracking features, not a learning journey for a first period.

What matters for her

Not made for under-13s

Period Calendar is rated 13+ on the App Store, and its privacy policy says the service does not address anyone under 13. Many girls get their first period before 13, and the age varies a lot. Soso is rated 9+ and was made for exactly those years.

Ads and an intimacy log

Period Calendar contains ads and records intimacy alongside ovulation and fertility. Soso has no ads and none of those features: it stays with puberty and the first years of cycles.

Soso starts before the first period

Period Calendar’s predictions come from periods already logged. Soso gives a girl who has not had her first period an estimate of when it may arrive, then narrows the window as she follows the signs of puberty: illustrated stages for breast and pubic hair development, and her height each month.

Where Period Calendar is better

Huge scale, no account needed, several profiles on one phone, a partner mode, pill reminders and Wear OS. For an adult who wants all of that and accepts ads, it does a lot.

Frequently asked questions

Does Period Calendar contain ads?

Yes. Its Google Play listing says “Contains ads”, and the iOS version lists advertising too. Soso has no ads.

What age is Period Calendar for?

Its iOS version is rated 13+, and its privacy policy says the service does not address anyone under 13. Soso is rated 9+ on the App Store.

Does Period Calendar have an intimacy log?

Yes. It has an intimacy tracker, alongside ovulation and fertility. Soso has no intimacy log.

Does Period Calendar track you?

On iOS, its App Store privacy label lists identifiers and usage data that may be used to track you across other companies’ apps, and health data linked to your identity. Soso declares no tracking.

Does Period Calendar need an account?

No, and that is a real strength. Soso does not need one either.

Does Period Calendar work before the first period?

It is built to track periods, ovulation and pregnancy once periods start. Soso gives a girl who has not had her first period an estimate of when it may arrive, and narrows it as she logs the signs of puberty.

Does Soso need an account?

No. There is no Soso account. Her cycle data is stored on her phone and never sent to our servers. If you turn on backup, it goes to your own iCloud or Google Drive.

Start the first cycle without drama

A gentle, educational and ad-free space to learn and track at your own pace.

Download Soso

Sources and transparency

Each source says what was checked and when it was consulted.

  • Soso privacy policy

    There is no Soso account, and cycle data is stored on the device and never sent to Soso’s servers. Backup is optional and goes to the user’s own iCloud or Google Drive.

    Accessed Oct 8, 2026

  • Soso on the App Store

    Rated 9+, with no advertising. The privacy label declares no data used to track you and no data linked to you. Describes the first-period estimate and the First Period Prediction Pack.

    Accessed Oct 8, 2026

  • Soso Medical Sources

    The age a first period usually arrives (NHS, Cleveland Clinic, StatPearls) and how many girls have started by each age (a US national survey).

    Accessed Oct 8, 2026

  • Period Calendar on Google Play

    Contains ads, 100M+ downloads, no account required, and records intimacy, BMI, ovulation, fertility and pregnancy.

    Accessed Oct 8, 2026

  • Period Tracker Period Calendar on the App Store (iOS version)

    Rated 13+, contains advertising, and the privacy label lists identifiers and usage data that may be used to track you.

    Accessed Oct 8, 2026

  • Period Calendar privacy policy

    The service does not address anyone under the age of 13.

    Accessed Oct 8, 2026