For a first period or a younger girl, start with Oky. UNICEF makes it for girls aged 10 and up, and it explains periods as well as tracking them. Plum is a good fit for teens 13 and up who want a simple tracker with no ads and like seeing when their friends’ periods are due. If you want something already on the phone, Apple’s Cycle Tracking is in the Health app. Whatever you pick, a period app’s predictions aren’t contraception.
How we chose
We make Plum, one of the apps here, and there are no affiliate links on this page. We read each company’s own pages and App Store listings on October 12, 2026. We picked apps a parent would be comfortable with. That means a fitting App Store age rating, no ads aimed at kids, and no way for strangers to see anything. We also looked at whether each app teaches the basics, since a first tracker is often a first lesson too.
What a teen needs from a period tracker
Mostly a simple way to count. ACOG’s advice for a first period is to mark the first day of bleeding as day 1 and keep counting until the next one. It also says cycles of 21 to 45 days are normal and can take six years or more to become regular. So the best teen app keeps logging quick, explains what’s normal, and doesn’t promise a precise date. The NHS says the first periods can take some months to settle into a pattern.
Oky, for a first period and learning the basics
Oky is made by UNICEF. Its App Store listing describes it as an app for girls aged 10 and up and gives it a 9+ rating. It tracks how a period affects your body and mood, gives personal predictions, and has facts and tips about staying healthy. Its release notes mention an encyclopedia and avatars you can design. A recent update lets several people keep their own private Oky account on one phone, which helps when siblings share a device.
Oky costs nothing, and the listing shows no in-app purchases. Its privacy label lists only identifiers, usage data and diagnostics, none of it linked to you, and nothing under Data Used to Track You. The US listing is in English. For a girl who hasn’t started yet, or has just started, it’s the most useful app on this page.
Plum, for teens 13 and up who want simple and ad-free
Plum is rated 13+ on the App Store. Logging a day takes a tap or two, and Plum reminds you before your period, three days ahead and the evening before, so it doesn’t catch you out at school. You choose which things to track, so a teen can keep it to period days and a few symptoms like cramps or mood. You can also hide the fertile window and ovulation from the calendar. Logging, predictions and reminders come with the app at no cost, and Plum Premium adds insights and the full set of phase tips.
The part teens tend to like is private groups. Friends join by an invite link that one of them sends, so a group is only people you already know. Each member sees the others’ period days on one shared timeline, so you know whose period is due. Symptoms and moods are never shared, and every group has its own switch to stop sharing. Our page on what a group can see lists every field.
Plum has no ads, never sells data and never asks to track you. You sign in with Apple or Google, your data is stored encrypted, and you can delete the account from inside the app. It’s iPhone only.
Apple Cycle Tracking, for the one already on the phone
Cycle Tracking is part of the Health app on every iPhone. Apple says you can log your period and track symptoms, spotting and more, and turn on notifications for when your next period is coming. There’s nothing to download and no new account to make. It has no lessons or tips, so pair it with a trusted source for the basics.
Clue, for older teens who want the most detail
Clue says it supports you from first period to perimenopause, with over 200 symptoms and more than 400 articles. It’s rated 13+. It’s a big app, and its privacy label lists Identifiers under Data Used to Track You. For an older teen who wants to read a lot, it’s a solid choice.
Side by side
| App Store age rating | Teaches the basics | Ads | Sharing | |
|---|---|---|---|---|
| Oky | 9+, made for girls 10 and up | Yes, facts, tips and an encyclopedia | Not stated. No in-app purchases listed | None |
| Plum | 13+ | Phase tips, one full tip a day without Premium | None | Private groups of friends by invite, sharing period days and workout days |
| Apple Cycle Tracking | Built into iPhone | No | None | Not stated |
| Clue | 13+ | Yes, over 400 articles | Not stated | Clue Connect |
| Flo | 13+ | Yes, a health library | Not stated | Flo for Partners |
A note for parents
Look at the App Store age rating and privacy label together before you say yes. The label’s Data Used to Track You section tells you whether an app shares data for advertising. Then sit down for five minutes and set the app up side by side. Let your teen choose what to track, since it’s their log. And if a period is very heavy, lasts more than 7 days, or hasn’t started by 15, ACOG says to see a doctor.
If you’d like to see her dates and have her see yours, our guide to a period tracker for a mom and daughter compares the apps that share both ways.
