Privacy Policy

Last updated: October 2026

Tidebook is a private symptom journal for endometriosis and adenomyosis. What you log stays on your iPhone. There’s no account and no server, and I never see your data.

Data Collection

Tidebook doesn’t collect any data. What you enter is stored only on your iPhone, in the app’s database:

• how each day went, with any notes, tags and pain locations
• flares, with their times, strength and what you noted during them
• period days and cycle settings
• medications and supplements, changes to them, and doses taken
• your settings, such as privacy mode and reminders

There’s no sign-in and nothing is sent to me or anyone else. iOS encrypts the database, and it can’t be read while your phone is locked.

Phone Backups

Tidebook doesn’t sync through iCloud. Your phone’s own iCloud and computer backups include Tidebook, unless you turn on “Leave out of iCloud Backup” in More → Privacy. iCloud Backup is end-to-end encrypted only if Advanced Data Protection is turned on for your Apple Account.

Apple Health

If you allow it, Tidebook reads period days and spotting, sleep, resting heart rate, heart rate variability, sleeping wrist temperature and steps from Apple Health, and, on iOS 26 and later, the medications you choose and their doses. It adds the period days you mark in Tidebook to Apple Health. You choose each kind of data in Apple’s permission screen and can change it at any time in Settings.

Health data is used only to show your days in Tidebook. It’s kept on your phone as one summary a day, never used for advertising, never shared, and never stored in iCloud by the app.

Widgets, Lock Screen and Notifications

Widgets, the Lock Screen and Live Activities can show today’s level, the cycle day and a flare in progress. Your notes, medications and history stay in the app. With privacy mode on, they use neutral words.

The daily reminder is a local notification scheduled on your phone. No push service is involved.

Siri & Shortcuts

Siri, Shortcuts, widgets and Control Center actions run on your phone through Apple’s App Intents. Nothing is sent to external servers.

Voice Notes

If you use voice notes, speech is turned into text on your phone using Apple’s on-device speech recognition. No recording is kept, and nothing is sent anywhere.

Data Export & Import

You can export an encrypted backup file, protected by a password you choose. Tidebook never keeps the password. After an export, iOS may offer to save it in your password manager; that’s your choice, and Tidebook can’t see it. You can also export your data as CSV files, which aren’t encrypted. Data read from Apple Health is left out of both unless you include it.

Exports are made on your phone and go only where you send them. Restoring a backup file replaces what’s in Tidebook on that phone.

Analytics and Tracking

Tidebook has no analytics, tracking, advertising or third-party SDKs. If you’ve chosen to share diagnostics with app developers in your iPhone’s settings, Apple may send me crash reports, which don’t include what you’ve logged. This website has no analytics or tracking scripts either.

Purchases

Tidebook Plus is bought through the App Store. Apple handles the payment, and I don’t receive your payment details.

Data Sharing

I don’t share, sell or receive your data. There’s nothing to share: it never leaves your phone unless you export it.

Data Deletion

More → Delete everything removes all of Tidebook’s data from your phone, and so does deleting the app. Copies in your phone’s backups and files you’ve exported stay until you delete them. Period days Tidebook added to Apple Health stay in Apple Health, where you can delete them.

Children’s Privacy

Tidebook doesn’t collect personal information from anyone, including children.

Changes to This Policy

If this policy changes, the new version will be posted on this page with a new date.

Contact

Questions about privacy? Email me at hello@gregbell.dev.