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All comparisons

Soso vs. Luna Teen

Luna Teen is a good teen tracker. Soso starts before the first period.

Luna Teen Period Tracker, made by a middle-school teacher, is one of the few period apps built for tweens: no ads, nothing in its App Store tracking label, no account needed to track, and nothing to log about sex or fertility. Soso shares those values, and goes further before the first period, with an estimate of when it may come (an estimate, not a date) and puberty tracking, in Portuguese as well as English.

Reviewed Oct 9, 2026

Soso is best for

A girl who has not had her first period yet, or a family that wants the app in Portuguese, rated 9+, with backup in their own iCloud or Google Drive.

Luna Teen is best for

An English-speaking teen who already has periods, and a parent who wants to link to up to four children.

Our verdict

Luna Teen is the closest app to Soso, and a good, private choice. For a girl who has not had her first period yet, or a family that wants Portuguese, choose Soso: it gives an estimate of when her first period may come (an estimate, not a date), follows puberty, is rated 9+ and keeps backups in your own account. Luna Teen is stronger if you want a parent link.

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.
Luna Teen:Teens and tweens: its App Store subtitle is “Tween & First Period Calendar”. Rated 13+ on the App Store; its terms say a parent must agree to them for a child under 13.
Before the first period
Soso:A whole experience for girls who have not had their first period yet. She gets a first estimate of when it may arrive, and with the First Period Prediction Pack 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.
Luna Teen:Lessons and answers to questions. Neither its store listing nor its website mentions an estimate of a first period, and its own lesson says the exact time is hard to predict.
Puberty body changes
Soso:With the First Period Prediction Pack, 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.
Luna Teen:Not in its list of what you can log, which covers flow, symptoms, moods and notes.
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.
Luna Teen:App Store label: no data used to track you and nothing linked to you, though it lists health data, not linked to you, used for analytics. Data is encrypted on the phone, when stored and in transit.
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.
Luna Teen:Optional. Backup and the parent link need an account and are part of its Luna+ subscription, and backups are stored on Luna’s servers.
Ads
Soso:No ads.
Luna Teen:No ads.
Sex, fertility and pregnancy
Soso:None. No sex log, no fertility window, no pregnancy mode.
Luna Teen:Nothing to log. Ovulation and pregnancy appear only in its lessons and answers.
Cycle tracking
Soso:Period, flow, spotting, discharge, mood and symptoms, in a calendar made for the first cycles.
Luna Teen:Flow, spotting, symptoms, moods and notes, with predictions designed for young cycles, which it says can run about 20 to 45 days.
Devices
Soso:iPhone, iPad, Android and Apple Watch, with Siri.
Luna Teen:iPhone, iPad and Android. No Apple Watch.
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.
Luna Teen:Interactive lessons and a Question Box citing sources such as KidsHealth. Ask Luna answers questions with AI, starting from answers written by public health professionals.
Languages
Soso:English, Portuguese and six more languages.
Luna Teen:English only, including in the Brazilian App Store.

What matters for her

The closest app to Soso

Luna Teen and Soso are both built for girls, not adults: no ads, nothing in the App Store tracking label, no account needed to track, and no sex or fertility logging. That puts Luna Teen well ahead of the big apps.

Soso starts before the first period

Before a first period, Luna Teen offers lessons. Soso gives her 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. It is an estimate, not a date: a first period can come earlier or later.

Portuguese, 9+, and your own backup

Luna Teen is only in English, even in the Brazilian App Store, and is rated 13+. Its backup needs an account and lives on Luna’s servers. Soso is rated 9+, speaks Portuguese and seven other languages, and its optional backup and sync go to your own iCloud or Google Drive, with no Soso account.

Where Luna Teen is better

A parent link for up to four children that keeps the child’s notes private, and a teacher behind it who updates it often. For an English-speaking family that wants a parent link, it is a strong choice.

Frequently asked questions

Is Luna Teen a good app for girls?

Yes. It is one of the few made for them: no ads, nothing in its App Store tracking label, no account needed to track, and nothing to log about sex or fertility. Soso shares all of that, and adds an estimate of when her first period may come (an estimate, not a date), puberty tracking and Portuguese.

Does Luna Teen predict the first period?

Neither its store listing nor its website mentions a first-period estimate. Before a first period it offers lessons, and its own lesson says the exact time is hard to predict. Soso gives an estimate that narrows as she logs the signs of puberty. It is an estimate, not a date.

Is Luna Teen available in Portuguese?

No. It is in English only, including in the Brazilian App Store. Soso is in Portuguese, English and six more languages.

What age is Luna Teen for?

It is rated 13+ on the App Store, and its terms say a parent must agree to them for a child under 13. Soso is rated 9+.

Does Luna Teen need an account?

Not to track. Backup and the parent link need an account and are part of its Luna+ subscription, and backups are stored on Luna’s servers. Soso has no account, and its optional backup goes to your own iCloud or Google Drive.

Does Luna Teen have ads?

No, and its privacy policy says it contains no advertising SDKs. Soso has no ads either.

Does Luna Teen have a parent link?

Yes. A parent can link up to four children without being able to read the child’s notes. It is one of Luna Teen’s real strengths.

Does Luna Teen work on Apple Watch?

No. It runs on iPhone, iPad, Mac and Android. Soso works on Apple Watch, with Siri.

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

  • Luna Teen on the App Store

    Subtitle “Tween & First Period Calendar”, rated 13+, data encrypted on the device, and a privacy label with no data used to track you and none linked to you. Runs on iPhone and iPad, English only.

    Accessed Oct 9, 2026

  • Luna Teen on Google Play

    An Android version, with in-app purchases and no “Contains ads” label.

    Accessed Oct 9, 2026

  • Luna Teen terms of service

    For a child under 13, a parent or guardian must read and agree to the terms on the child’s behalf.

    Accessed Oct 9, 2026

  • Luna Teen privacy policy

    No advertising SDKs. No account is needed to use the app; an account enables backup, stored on Luna’s servers. Ask Luna uses AI to tailor answers from a library written by public health professionals.

    Accessed Oct 9, 2026

  • Luna Teen features

    What can be logged: flow (including spotting), symptoms, moods and notes. Predictions built for young cycles of about 20 to 45 days.

    Accessed Oct 9, 2026

  • Luna Teen for parents

    A parent can link up to four children and sees everything except the child’s notes. Linking and backup are part of Luna+.

    Accessed Oct 9, 2026

  • Luna Teen lesson: your first period

    The exact time of a first period is hard to predict.

    Accessed Oct 9, 2026