SaiDay Privacy Policy

Last updated: October 29, 2026

What this policy covers

SaiDay is an app that turns your life into social-media-style diary posts. It is made by an independent developer. This policy explains what data the app touches, where it is kept, and what it never does.

We don't collect your diary

SaiDay has no cloud account system, no analytics, no ads and no tracking, and it never sends your diary to the developer. The only thing stored on a service the developer uses is your Profile Card, when you tap “Share” in “My Card” (see “Card links” below). Place search and maps, in-app purchases and ratings are handled by Apple's system services. When you share, export, or choose a backup folder in a cloud service yourself, the data goes to the destination you picked and is handled under that service's rules.

Data stored on your device

Post text, photos, moods, place names and coordinates, highlights, virtual characters and their interactions, notifications and settings are stored in the app's storage on your device. They may also be included in device backups you have turned on (iCloud or computer backups). In Settings › Data & Backup you can back up your whole diary, export the text or make a PDF, and decide yourself where those files go and who gets them. A backup file contains your diary and photos, so keep it as carefully as you would a diary. To delete the diary in the app, use “Reset All Data” or delete the app; files you exported or backed up separately must be deleted by you.

Automatic backup

Automatic backup is turned on when you pick a folder in Settings › Data & Backup. The app remembers its permission to that folder; afterwards, when you open the app, your chosen daily or weekly interval has passed and the diary has changed, it backs up the whole diary to that folder and keeps only the three newest automatic backups it created itself. If you pick iCloud Drive or another cloud service, the files are handled and synced by that service and never pass through the developer's servers. This is a backup file, not live sync between devices inside the app; you can stop automatic backup at any time and the files already created stay.

Widgets and Live Activities

The app and its own widget extension read a snapshot through shared storage on this device (an App Group); nothing is sent to the developer. The snapshot may include your local profile name and handle, simulated follower and interaction numbers, post dates, part of a caption and a thumbnail, used for Home Screen widgets and the boost countdown Live Activity. When “Lock Diary” is on, the widget snapshot leaves out captions and thumbnails, and so does the Live Activity. Content on the Home Screen and Lock Screen can be seen by people near you, so turn on the lock if you need to, or switch off the boost countdown in notification settings.

Location

Your current location is read only once, when you tap “Add Location,” to list nearby places. Your current location is never stored, updated in the background, or uploaded. The place name and coordinates you choose are saved in that post so they can be pinned on your own map. Place search goes through Apple's map service and queries are handled under Apple's privacy policy. Without location permission you can still search for a place or type one yourself.

Photos

Photos are picked with the system photo picker, so the app only gets the photos you choose and never accesses your whole library. When you choose “Save Image” while sharing a post, the system first asks whether the app may add that share card to your library; this permission can only add photos and can't see what's already there.

Sharing

When you tap “Share,” the app draws that post (optionally with its comments) or milestone as an image and hands it, with a short recommendation and SaiDay's App Store link, to the iPhone share sheet. Whether to send it, to whom and with which app is up to you; the app never sends anything on its own.

Card links

When you tap “Share” in “My Card,” the app stores the card's contents (name, handle, bio, personality and speaking style, favorite topics, the lines and typing habits you wrote) and a small card photo in a Google Firebase database used by the developer (Taiwan region), in exchange for a short link printed in the card's QR code. Anyone with the link can see the card in a browser or add it in SaiDay. If you change your card later, the app puts the new version on the same link (when you leave “My Card” or open the app); a shared card's expiry is extended automatically when you open the app, and it expires after 30 days without opening the app, after which nobody can read it. You can also take it back early with “Stop Sharing Link” in “My Card.” People who added your card read the link only when they tap “Check for Card Update” themselves; the app never reads it automatically and never sends anything back to you. Your diary, comments and other photos are never uploaded. When you're offline the app falls back to the original method: the card's contents are printed in the QR code and stored nowhere. “Report” on the card web page records only the reported card's ID and the time. When you connect, Google handles the technical data needed for the connection (such as your IP address) under its own policy.

Version check

When you open the app (at most once every six hours), it reads a public configuration from a Google Firebase database used by the developer to see whether this version can still be used and whether a seasonal event should be shown; versions that are too old ask you to update in the App Store. This only reads and never writes, and it never sends your diary, your card or any personal data. When you connect, Google handles the technical data needed for the connection (such as your IP address) under its own policy. The app works as usual offline.

Notifications

Notifications are scheduled by the app on your device, including the “Daily Journal Reminder” you turn on yourself; there is no push server. You can turn them off in Settings › Notifications.

Purchases

SaiDay Plus, SaiDay Pro and post boosts are handled through Apple's In-App Purchase. The developer never receives your payment details; Apple tells the app your purchase status. Saved boosts and your monthly boost allowance are recorded on this device and currently don't sync across devices.

On-device understanding and external AI connections

“Comments that understand your caption” is free and works on iPhones that support Apple Intelligence, run iOS 26 or later, have Apple Intelligence turned on and have the on-device model available; you can turn it off in Settings. It reads only the caption, the chosen topic and your mood, on the phone. It does not read photos, places, your account or custom character settings, and it never sends your diary to an outside AI service; comments are still picked from lines built into the app. Sad and self-harm posts are not given to the on-device model and get the existing gentle lines instead. When the feature isn't available the app falls back to its built-in lines. The released app has no external AI connection; only the developer's own test builds can be set up by hand to send post text, photo thumbnails, places, topics and custom character settings to Anthropic's API, which is covered by that service's privacy policy.

Images in the app

Profile pictures for the built-in virtual characters and the sample images are installed with the app and never loaded from the internet. All built-in portraits are AI-generated fictional people, not any real person. You can also pick your own photos as your profile picture or a custom character's picture; like your diary, these stay on your device unless you share or back them up yourself.

Children

SaiDay is not designed for children under 13 and does not collect anyone's personal data.

Changes to this policy

When this policy changes, this page and the date at the top are updated.

Contact

If you have questions about this policy, contact the developer through the contact details on the App Store page.