Orionian

Cycle

A period tracker that keeps your journal on your phone and is honest about what it can predict. No account, no ads, no internet access.

Coming to Google Play

For Android 8 and later

A range, not a promise

Your next period is shown as a range of days, with the most likely day and what it's based on. The range narrows as you log, and twenty dots on the cycle line show where the chance gathers.

History shows how close each prediction came. Long and irregular cycles count in full: a cycle that looks like a missed log is asked about, never quietly dropped.

Day 21 of this cycle

Oct 30 to Nov 5

Next period, likely. Most likely Nov 2.

Based on your last 6 cycles, 27 to 29 days long.

No internet access. None.

Cycle was built without Android's internet permission, so Android won't let it connect, even if we wanted it to.

What you log about your body stays on your phone. Cycle has no account, no ads, no analytics and no crash reports, and it can't send what you log anywhere. Files leave only when you save or share them.

Permissions, each with one job

Show notifications POST_NOTIFICATIONS
Reminders, once you turn one on. On Android 13 and later, Android asks you then.
Run at startup RECEIVE_BOOT_COMPLETED
Puts your reminders back after a restart. It listens only while a reminder is on.
Fingerprint or face USE_BIOMETRIC
The lock, if you turn it on: Android's own fingerprint, face or screen lock prompt. Cycle only learns whether it was you.
Google Play billing com.android.vending.BILLING
Buys Cycle Pro through the Play Store app on your phone.
Health Connect's cycle records android.permission.health.*
Only after you tap Connect, on Health Connect's own screen: bring in what other apps saved there, and write what you log, if you turn that on. The privacy policy lists each one.

That's the whole list. The app's build fails if anything else ever appears in it.

Never lose a day

  • Google backup, end to end encrypted with your screen lock, when backup is on in your phone's settings.
  • Phone to phone, when you set up a new Android phone.
  • A backup file sealed with a passphrase, to keep anywhere. Without the passphrase no one can open it, Orionian included.
  • A spreadsheet file of every day, for a doctor, another app or an iPhone.

Bring your history from another app's export file or from Health Connect, and write to Health Connect if you choose. How each way works, and how to back up now: backup and restore.

Discreet by default

  • Reminders for a period coming or late, a pill, ring, patch or injection, and a daily log, in neutral words you can change. Hidden on the lock screen unless you choose otherwise.
  • Lock Cycle with your fingerprint, face or screen lock.
  • Cycle stays out of screenshots, screen sharing and recent apps unless you allow them.
  • The widget shows the day of your cycle and nothing else, unless you choose one of Pro's.

The privacy policy says all of this in full.

What you get

  • Cycle's main screen: day 21, the next period likely Oct 30 to Nov 5, most likely Nov 2.
    A range, not a promise
  • Logging a day: flow, spotting, pain, symptoms, moods and a note, each saved at the tap.
    Log a day, every tap saves
  • History: a typical 28-day cycle, and each period's start against what was predicted.
    See how close each prediction was
  • Backup and export: Google backup, phone to phone, a backup file sealed with a passphrase, a spreadsheet.
    Never lose a day
  • Reminder settings: a pill reminder, a daily log, and reminders hidden on the lock screen.
    Reminders stay off the lock screen
  • Perimenopause mode: 20 days since the last period, with a wide range for cycles that vary a lot.
    Made for irregular cycles too
  • Log a day in a tap or twoFlow, spotting, pain, symptoms, moods, your own tags and a note. Every tap saves. “Period started today” is one tap, with undo, and any day you missed can be filled in later.
  • History and patternsYour typical cycle and period, how much they vary, and every cycle with its period. If something stands out over six months, such as cycles that vary a lot or bleeding between periods, Cycle says so in plain words and suggests mentioning it to a doctor or nurse. It never names a condition.
  • A report for your doctorThe last 12 months in a PDF to share.
  • Pregnancy and perimenopausePregnancy mode pauses predictions. Perimenopause mode tracks bleeding and symptoms without expecting regular cycles, and leads with the days since your last period.
  • Breastfeeding and hormonal contraceptionThey change what's predicted: bleeds on the pill aren't counted as periods.
  • An estimated fertile windowOff unless you turn it on, and hidden when your dates can't support it. An estimate. Not a way to prevent pregnancy.
  • In 17 languagesWith TalkBack and large text throughout.
  • Light and darkFollowing your phone.

Cycle Pro

Everything above is free, for good. Pro is one purchase, with no subscription, and adds the temperature chart: your temperature on waking and your mucus, drawn cycle by cycle and read with the symptothermal method's temperature and mucus rules. Logging them is part of the app. Pro also adds two widgets, the cycle line and the likely dates of your next period, and two app icons: a dark one and a plain one.

Get Cycle

Coming to Google Play

For Android 8 and later.

Cycle is not a medical device and does not diagnose, treat, cure, or prevent any medical condition. Its predictions are estimates. Not a way to prevent pregnancy. If something worries you, talk to a doctor or nurse.