Private Cycle Journal

Cycle Tracker is a period and symptom tracker built around one rule: your data never leaves your phone.

There are no accounts to create, no servers to sync with, and no analytics or ad SDKs watching what you log. Everything from period dates, symptoms, notes, and predictions are all encrypted on your device and stays there unless you personally choose to export a backup.

WHAT YOU CAN TRACK • Period start/end dates • Flow intensity, mood, cramps, bloating, digestive symptoms, sleep, stress, and more • Your own custom symptoms • Free-text notes, searchable later so you can find "did I feel this way last month?" in seconds • A one-tap "log today, nothing notable" shortcut for days you don't want to fill out a full form

ON-DEVICE PREDICTIONS • Cycle length and ovulation window estimates, calculated entirely on your phone • Seasonal adjustment once you have enough history • Symptom timing and co-occurrence insights ("you tend to get headaches 2 days before your period") • Predictions ranges, with a confidence indicator that improves as you log more • A plain-language screen explaining exactly how every prediction is calculated

PRIVACY AND SECURITY, BY DEFAULT • Local database encrypted at rest (SQLCipher/AES-256) • Stack any combination of biometric unlock, PIN, password, and authenticator-app (TOTP) codes, and choose how many of them are required to unlock • Rate limiting with escalating delays on failed attempts • Optional auto-wipe after too many failed attempts • Optional decoy mode • Screenshot and screen-recording blocking • Jailbreak/root and app-tampering detection on launch • A neutral app name and icon by default

YOUR DATA, YOUR CALL • Manual, encrypted export whenever you want a backup • Import to restore on a new device • Configurable reminders to back up periodically, since nothing is ever backed up automatically

Built for anyone who wants real cycle and symptom insights without handing their health data to a company. No accounts. No cloud. No tracking beyond the tracking you're actually here for.