Period diary, symptoms and reminders
Record periods, symptoms and mood; revisit dates and prepare with reminders. The diary, calendar and predictions work offline. Core tracking will always remain free.
Details ↗PERIOD TRACKER FOR IPHONE
Period &
cycle tracker.
AI support.
Track your cycle and talk it through
with your AI assistant.
HeySis core features will always remain free. Premium is optional and unlocks additional features.
iOS 26+
MAKE IT YOUR CHOICE
Compare period trackers.
Find your fit.
Every body and every routine is different. Compare the experience, privacy and practical details — then choose what feels right for you.
HeySis
FloTRACKER COMPARISON
HeySis vs Flo
Pricing, free features and doctor reports.
Compare ↗HeySis
ClueTRACKER COMPARISON
HeySis vs Clue
Detailed tracking, AI and history import.
Compare ↗HeySis
StardustTRACKER COMPARISON
HeySis vs Stardust
Sharing, screenshot import and subscriptions.
Compare ↗HeySis
CyclesTRACKER COMPARISON
HeySis vs Cycles
Partner access, reminders and devices.
Compare ↗HeySis
Apple HealthTRACKER COMPARISON
HeySis vs Apple Health
What a dedicated iPhone tracker adds.
Compare ↗App icons and names belong to their respective owners and identify the products being compared.
AI ASSISTANT
An AI assistant
for cycle questions.
Sometimes you want to ask a question, not interpret a chart. The AI assistant uses your cycle and well-being context to respond in everyday words.
Online answers need your consent: an AI provider processes your message and the context needed to reply. The AI assistant can make mistakes and does not diagnose.
How your data and AI work
PERIOD CALENDAR
Your cycle history.
In one place.
See logged days by month or year, revisit how you felt on a particular day and prepare for your next cycle.
The calendar shows estimated period dates, ovulation and the fertile window. These are estimates: they help with planning but do not confirm ovulation and must not be used as contraception. Records and predictions work offline.
Explore the features
CYCLE EDUCATION
Understand your cycle.
A little at a time.
Short reads about cycle phases, PMS, well-being and fertility, alongside your own entries.
Choose a topic and read at your own pace. The library includes free articles and extended Premium content. Educational reading can help you understand terminology and prepare questions for a healthcare professional.
Explore the features
SYMPTOM AND MOOD DIARY
Log with a tap.
What matters to you.
Choose the entries you need. Mood today, sleep or symptoms tomorrow. You can return to a day and add more later.
You decide how much to record and how often to open your diary.
YOUR CIRCLE
Share how you feel.
With your people.
Invite a partner or friends to Circle. It is easier to support each other when you know how someone feels today.
Choose what to share and stop sharing whenever you want. Invitations and basic status are free; detailed insights and selected interactions are Premium features. An invited companion does not need their own paid subscription to join.
How Circle works
THE EVERYDAY ESSENTIALS
HeySis period tracker features.
For your everyday life.
Circle: share how you feel with people you choose
Let a partner or friend understand how you feel. Invitations and basic status are free; deeper insights are Premium. You choose what to share.
Details ↗A free PDF report for your doctor
Bring recorded dates to your appointment. A free PDF gathers up to six recent cycles and recent diary entries on your phone. AI conversations are excluded.
Details ↗Move period history from calendar screenshots
Keep your recorded period dates when switching apps. HeySis recognizes calendar screenshots on your iPhone. Review the result: screenshots do not transfer every note or symptom.
Details ↗An AI assistant for questions about your cycle
Ask in your own words, with relevant diary context. Online AI requires consent and has a free message allowance; Premium raises it. It provides educational support, not diagnosis.
Details ↗Apple Health: separate read and write permissions
Import supported Health records or share period flow and selected symptoms with separate permissions. Personal notes and AI chats are not written to Apple Health.
Details ↗Pregnancy and cycle education
Follow pregnancy by week and keep your entries for free. Read about cycle phases. Premium adds selected baby illustrations, weight analytics and an extended article library.
Details ↗What stays on the phone and what goes online
Your diary stays on the device by default. Online AI, sync and Circle have separate access choices. No in-app ads or sale of user data.
Details ↗PERSONAL MEANS PERSONAL
Your cycle data.
Your privacy.
Local records, online AI, sync and Circle each have their own access choices.
An on-device diary
Your diary is stored on your iPhone by default. Sync is a separate choice; synced diary content is end-to-end encrypted.
Online AI with consent
An AI provider receives your message and relevant context after you consent. You can use the diary without online AI.
No ads or data sales
There are no in-app ads and user data is not sold. Our privacy policy explains service providers and product analytics.
You control Apple Health access
Reading records and writing period flow and selected symptoms need separate permissions. AI chats and personal notes are not written to Health.
THE HEYSIS APPROACH
A period tracker
that leaves room for you.
Plain language
Cycle questions deserve understandable explanations.
Your own pace
One entry is already a way to remember today.
Your choice
You decide what to record and what to share.
A little kindness
Your diary fits around life. A missed day can stay empty.
GOOD QUESTIONS
Period tracker questions.
Answered.
What is the best period tracker?
The best fit depends on your needs. Consider HeySis if you want an on-device iPhone diary, history import and a conversation with the AI assistant. Our journal compares HeySis with Flo, Clue, Stardust, Cycles and Apple Health.
Is HeySis free?
HeySis core features will always remain free. Optional Premium unlocks additional features, including more AI messages, deeper insights and selected Circle features. Local subscription prices are shown in the app.
Does it work offline?
The local diary, calendar and predictions work offline. Online AI answers, cloud sync and Circle sharing use the internet.
What can a calendar screenshot import?
It imports recognized, logged period days. Calendar layouts vary, so check the result after import. Screenshots do not transfer every symptom, note or prediction.
Does HeySis write to Apple Health?
Yes, if you separately enable sharing and grant iOS permission. Period flow and selected symptoms can be written; AI chats and notes are not shared.
Can an AI assistant replace a doctor?
No. The AI assistant provides educational support and does not diagnose. Cycle predictions are estimates and must not be used as contraception.
Who can see my entries?
Your diary is stored on your iPhone by default. Online AI, sync, Circle and Apple Health have separate access choices. Read how data is handled.
How do I delete my account and data?
Open Profile → Delete all data. Use this feature before uninstalling the app to delete server data as well. Follow the deletion guide.
Get HeySis.
Your period tracker.
For iPhone with iOS 26 or later