Your data never leaves your phone
Track your cycle without handing it to anyone.
Sathi follows your period and your perimenopause on the device in your hand. Your logs are stored on your phone. Backups are encrypted before they leave it — with a key we do not have.
Free to track. No account needed to start.
Three ways to use it
You choose during setup, and the whole app changes to match — the home screen, what you can log, what the reports show.
Your period
Cycle length, flow, cramps, mood. Predictions that say how confident they are rather than pretending to certainty.
Perimenopause
Hot flashes, night sweats, sleep, brain fog. Built for the transition, not bolted onto a period tracker as an afterthought.
Both at once
Still bleeding and still changing. One app that does not make you choose which half of your body to describe.
Privacy that is built, not promised
Most apps ask you to trust a policy. A policy can change on a Tuesday. These are properties of how Sathi is put together.
- It lives on your phone
- Your cycle history is a database on the device. The app works with aeroplane mode on, because that is where the data already is.
- Backups are sealed first
- Turn on backup and your phone encrypts the bundle before uploading it. We hold ciphertext. There is no screen in our admin tools that could show your symptoms, because we never receive them.
- No account to start
- Install it and track. An account only matters when you want a second device.
- Nothing is sold
- Sathi is paid for by subscriptions. That is precisely why it does not need to be paid for with your data.
What you get
Patterns you would not spot yourself
Sathi reads your own logs back to you — which nights with poor sleep also had hot flashes, when your cramps actually start. Real numbers from your data, not horoscopes.
A report your doctor can use
A short PDF of your recent cycles and symptoms, in the date range you choose. The things a GP would otherwise ask you to remember in a ten-minute appointment.
It tells you when to ask someone
If your logs show a pattern worth raising with a clinician, Sathi says so — free, whether or not you ever pay us.
Fifteen languages
Including Bengali, Hindi, Arabic and Spanish, with the calendar, week start and number formats that go with them.
Free to track. Pay only for more.
Tracking is the app. It is not a trial, and it does not expire.
Free
Everything you need to track.
- Every kind of logging
- Calendar and next-period prediction
- Three months of history
- Health warnings
- Export your own data
Sathi Pro
7-day trialEverything in Free, and:
- Shareable reports for your doctor
- Symptom patterns and correlations
- Your full history, not just 3 months
- Backup and a second device
Priced in your own currency. Cancel any time through the App Store.
Questions people ask
Do I need an account?
No. You can install Sathi and start tracking without signing up for anything. An account only becomes useful when you want a backup or a second device.
Can I use Sathi for perimenopause rather than periods?
Yes, and it was built for that as much as for cycle tracking. During setup you choose whether you are tracking your period, tracking perimenopause, or both, and the whole app changes to match — the home screen, what you can log and what the reports show.
How accurate are the predictions?
They improve with data. With one logged cycle Sathi assumes an average length; with three or more it predicts from your own recent cycles and tells you how confident it is. If you have marked your cycle as irregular it widens the range rather than pretending to a precision it does not have.
Where is my data stored?
On your phone. Sathi keeps your cycle and symptom history in a database on the device itself, and the app works fully offline. If you turn on backup, what leaves your phone is encrypted first with a key only you hold — we store the encrypted bundle and cannot read it.
Can Sathi staff read my logs?
No. Backups are encrypted on your device before they are uploaded, and the key never reaches our servers. That is a property of how the sync works rather than a policy we promise to follow — there is no screen anywhere in our admin tools that could show your symptoms, because the data arrives as ciphertext.
Do you sell or share my data?
No. We do not sell data, and we do not share it with advertisers or data brokers. Sathi is paid for by subscriptions, which is the whole reason it does not need to be paid for by your data.
How do I delete everything?
Settings → Privacy & Data → Delete all data. It removes your account, every log, every period and every backup. You will be asked to type DELETE to confirm, because it cannot be undone.
What is in the GP report?
A short PDF of your recent cycles, the symptoms you logged and how they moved over time — the things a doctor would otherwise ask you to remember in the appointment. You choose the date range, and whether your name is on it.
Is the share link private?
The report is encrypted before it is uploaded, and the key travels in the part of the link after the # — which browsers never send to a server. So the link opens the report for whoever you give it to, and we still cannot read it.
What do I get for free?
All tracking, the calendar, your next-period prediction, three months of history, health warnings, and exporting your own data. Sathi Pro adds shareable reports for your doctor, symptom patterns, your full history and backup across devices.
Are health warnings behind the paywall?
No, and they never will be. If your logs show a pattern worth raising with a doctor, Sathi tells you whether or not you pay us.
How do I cancel?
Through the App Store, like any other subscription: Settings → your name → Subscriptions on your iPhone. Sathi never charges you directly, so cancelling is entirely in Apple’s hands and takes effect at the end of the period you have paid for.
Start tracking tonight
Free, no account, and nothing leaves your phone unless you ask it to.
Download for iPhone