-- so greetings feel a little more like yours.
Your history is stored only in this browser. If you clear your browsing data or switch devices, it's gone for good unless you export a backup.
Tap a day for details. Long-press (or hold) a day to quick-add a log. Swipe left/right to change months.
Observations from your own logged data, not medical advice.
Used only for greetings inside the app. Never leaves this device.
You haven't backed up yet.
The full backup is the only file you can re-import. Keep it somewhere safe -- cloud storage, email to yourself, a USB drive.
Two CSV files (periods and daily logs) for viewing in Excel or Sheets. This is for reading your numbers, not a backup -- it can't be imported back in, and it leaves out journal entries, photos and voice notes.
Use this to move your data to a new device or browser. Importing replaces everything currently stored here -- export first if you want to keep both.
Home screen
- The ring shows your current cycle day and phase.
- Next period and fertile window are estimates, each labeled with a confidence: high, medium, or low, based on how many cycles you've logged.
- With fewer than 2 periods logged, CycleSync says so plainly instead of guessing.
- Tap the "Coming up" card to see upcoming appointments and reminders.
Calendar
- Tap any day to see its details, including logged symptoms, predictions, and cycle day.
- Tap "Log period starting here" to mark when a period began (sets the start date).
- Long-press (hold) a day to jump straight to logging symptoms for that date.
- Solid color means a logged period; dashed or dotted borders mean an estimate, never a fact.
- Swipe left/right on the calendar grid to change months.
- Today's date is highlighted with a border.
Insights & Journal
- Tap the pencil button to quick-log symptoms -- 14 sliders (0–10) for things like cramps, sleep quality, energy, mood, flow, and more.
- The Journal tab is for freeform entries: rich text formatting, photos, voice notes, and tags.
- Insights only shows a pattern once you have enough logged history to back it up (typically 3+ cycles).
- Switch between Stats, Patterns, and Charts tabs to view different aspects of your cycle data.
Your data & backups
- Everything you log stays in this browser's local storage. No accounts, no analytics, nothing ever uploaded.
- Clearing your browser data deletes your history for good.
- Use the "Back up your data" card above to export a copy you control (JSON format), regularly.
- JSON backups can be restored to move your data to a new device or browser.
- CSV exports are for viewing in spreadsheet apps only and cannot be restored.
Checking...
Everything you enter is stored in this browser's own database, on this device. No accounts, no analytics, no trackers, and the page makes no network requests at all after it loads.
This locks the screen, like a phone lock -- it does not encrypt the data itself. See the note below.
The PIN lock hides the screen; it does not encrypt stored data. Anyone with direct access to this browser's storage (e.g. via devtools) could still read it. True encryption-at-rest is a bigger change with its own trade-offs (a forgotten PIN would make data unrecoverable) and isn't enabled here.
This is a browser-based app, not a native iOS/Android app, so it cannot access HealthKit, Health Connect, or wearable SDKs directly -- those require native platform code a web page cannot run. Nothing below is faked or simulated.
Notifications are generated locally by your browser. They can only appear while this app is open in a tab -- background delivery would require a push server, which this app will not use.
Deleting a period never erases it immediately -- it moves here first, and stays until you restore it or erase it yourself.
Permanently erase all periods, symptom logs, journal entries, appointments and settings from this device. This cannot be recovered.