For the Cairn appEffective: 25 August 2026Last updated: 25 August 2026
The short version
We run no servers. This app never sends your events to any server controlled by the developer — no such server exists.
Your data stays yours. Events live on your device; when your device is signed in to an Apple Account with iCloud available, the same data is stored in the iCloud private database of your own Apple Account so your own devices can sync.
No accounts, no ads, no analytics SDKs, no trackers, no third-party code. We do not collect, sell, or share your personal information.
Calendar and Contacts are read-only. They are read only when you start an import, and nothing in them is ever created, changed, or deleted.
1. Who provides this app
Cairn ("the app") is developed and published by gwongsam ("we"), an independent developer, for iPhone, iPad, Mac, and Apple Watch.
This policy explains how the app handles your information. One premise runs through all of it: the app has no backend server, and your events never reach us. Most of what follows therefore describes how data moves between your own devices and your own iCloud account.
2. What data the app handles
The following is created by you as you use the app and stored on your device:
Category
What it covers
Event data
Each countdown or count-up you create: title, date and time, time zone, direction, repeat rule and lunar flag, symbol and colour, category, note, pinned and archived state, creation date
Reminder settings
Per-event lead time, time of day, whether it is enabled, and whether it is time-sensitive
Settings and preferences
Language, default unit and progress style, lunar date display, whether the list shows times, daily digest switch and time, milestone reminder switch
Import candidates
Entries read from your system calendar or contacts when you start an import (see sections 4 and 7)
The app does not request, collect, or process: your legal name, government ID numbers, phone number, email address, payment information, location, health data, advertising identifiers (IDFA), or device fingerprints. The app has no account system — every feature works without registering or signing in.
Worth stating plainly: the names of events in a day counter can themselves be private — birthdays, anniversaries, medical dates, legal deadlines. That is exactly why the app is designed so that this data stays within your control: never uploaded to our servers, never handed to a third-party analytics tool.
3. Where the data lives
In three places, all of them yours:
Your device. Events are stored in an App Group container shared with the app's widgets — which is how widgets can show your events without making any network request.
Your own iCloud private database. When the device is signed in to an Apple Account and iCloud is available to the app, the same data is stored in the private CloudKit database of your Apple Account so your own devices stay in sync. That database is hosted by Apple and we cannot access its contents. You can see the current state under Settings › About › Storage; if iCloud is unavailable, the app falls back to local-only storage and keeps working.
Your Apple Watch. If you install the watch app, events are pushed to it directly from your iPhone over the system's watch connectivity channel — iCloud is not involved. The copy on the watch is a read-only mirror.
The app makes no network requests to any developer-controlled server; its networking capability exists solely for the system's iCloud sync. The app does not use CloudKit's public database, so your events are never visible to anyone else.
4. Device permissions
The app asks for the permissions below only when you use the corresponding feature. You can decline any of them and the rest of the app carries on working:
Permission
Used for
Notes
Notifications
Event reminders, the daily digest, milestone reminders
All are local notifications scheduled by your own device. There is no push server, and their contents never leave the device
Calendar
Importing calendar events as countdowns
Read-only. Read only while the import screen is open, and only for roughly the next two years. No calendar event is ever created, changed, or deleted
Contacts
Importing contact birthdays as yearly events
Read-only. Only names and birthday fields are read, to build the candidate list. No contact is ever created, changed, or deleted
What either importer reads is shown only on the import screen: only the entries you tick and confirm are written into the app, and the rest are discarded when you leave that screen. The app does not request location, camera, microphone, photo, or health access.
5. Diagnostics and crash data
The app contains no crash-reporting or performance-analytics SDK and never sends logs anywhere on its own.
If you have enabled Apple's "Share iPhone Analytics" and "Share with App Developers" in your system settings, Apple may provide developers with aggregated, de-identified crash traces and performance metrics. That data is collected and de-identified by Apple, contains none of your event contents, and you can turn it off in system settings at any time.
6. No purchases, subscriptions, or ads
The app is currently free: no in-app purchases, no subscriptions, no ad slots, no sponsored content, and no features behind a paywall. It therefore handles no payment information and integrates with no advertising or attribution network.
If paid features are ever introduced, all transactions will be handled by the App Store and we will never see your payment method; we would update this page and notify you in the app beforehand.
7. Import, export, and backups
Import. Besides Calendar and Contacts above, you can import a backup file previously exported from the app. The file is parsed locally on your device and is never uploaded anywhere. Importing appends rather than replaces.
Export.Settings › Data › Export Backup produces a Cairn-YYYY-MM-DD.json file containing all your events and reminder settings, then hands it to the system share sheet so you decide where it goes.
The backup file is plain, unencrypted JSON. That is deliberate — your data should remain readable without this app. It also means anyone who obtains the file can read all of it. Once the file leaves the app (saved to a cloud service, sent through a messaging app, dropped in a folder others can read), its security is between you and the service you chose, and is outside the scope of this policy.
8. Third parties: what we don't do
Spelled out, to avoid ambiguity:
We do not sell your personal information (including "sale" and "sharing" as defined under US state laws);
We do not use or disclose your information for targeted advertising; the app contains no ad SDK;
We integrate no analytics, event-tracking, A/B testing, crash-reporting, attribution, or profiling service;
The app contains no third-party SDKs — only Apple's own system frameworks;
We perform no automated decision-making or profiling;
We will not disclose your data to anyone for commercial purposes — we have no data to disclose.
The one third party involved is Apple: when you use iCloud sync, watch delivery, or system notifications, the relevant data is handled by Apple's system services. See the Apple Privacy Policy.
9. Retention and deletion
We hold none of your data, so there is no retention period on our side. How long anything lives is entirely up to you:
A single event: delete it in the app; with iCloud sync on, the deletion reaches your other devices.
Archiving: this only moves an event into Settings › Archive — it deletes nothing.
Everything on this device: delete the app and the local data goes with it.
The copy in iCloud: it belongs to your Apple Account; manage the app's storage and data under System Settings › your Apple Account › iCloud.
The copy on your watch: uninstall the app from the watch.
Backup files you exported: delete them yourself — we have no way of knowing where they are.
None of this requires contacting us, and we have no copies to delete on your behalf.
10. Your rights
Under applicable law — including the GDPR in the EU/EEA and UK, the CCPA/CPRA in California, and the PIPL in mainland China — you have rights to be informed about, access, copy, correct, supplement, delete, and port your personal information, and to withdraw consent.
In this app, exercising those rights requires neither contacting us nor waiting for our approval, because the data has been in your hands all along:
Right
How to exercise it
Access / copy
Everything is visible in the app; export a backup for a complete copy
Portability
Export a backup — it is ordinary JSON, readable in any text editor
Correction
Edit the event directly in the app
Deletion
See section 9 above
Withdraw consent
Revoke Calendar, Contacts, or Notification permission in system settings; turn off iCloud for the app
Object to automated decisions
The app performs no automated decision-making or profiling
If you believe your rights have not been honoured, or you have any question about this policy, contact us as described in section 15. We will respond within 30 days. You also have the right to complain to your local data protection authority.
11. Children
The app is not directed at children and does not knowingly collect personal information from them. Because nothing is ever transmitted to us, we hold no information about any user's age. If you are under the applicable age of digital consent in your country, please use the app with your guardian's consent and guidance; a guardian who wants the data removed can delete it as described in section 9.
12. Security
Local data is isolated by the system sandbox and protected by your device's own encryption and passcode.
iCloud transmission and storage are encrypted by Apple; see Apple's documentation for the details.
Delivery to Apple Watch uses the system's own connectivity channel and does not pass through us.
Exported backup files are not encrypted (see section 7) — store them sensibly.
We hold none of your data, so there is no "our database was breached" risk to speak of.
That said: the security of your device underpins all of the above. Set a passcode, enable biometrics, keep the OS updated, and be careful with jailbroken devices and backup files of unknown origin. No technical measure can guarantee absolute security.
13. International transfers
We neither receive nor transmit your personal information, so there is no cross-border transfer initiated by us. If iCloud is enabled on your device, where the data is stored is determined by Apple based on the country or region of your Apple Account (for example, iCloud in mainland China is operated by GCBD). For those arrangements and safeguards, see the Apple Privacy Policy and the iCloud terms.
14. Changes to this policy
If the way the app handles data changes, we will update this page and the "Last updated" date at the top. For material changes — introducing any form of data upload, for instance — we will make it prominent in the app and, where required, ask for your consent again. Previous versions of this page can be inspected in this site's public repository.
15. Contact
For any question about this policy or your data, email: gwongsam@gmail.com
Please mention the app version and your OS version — it helps us answer faster.
Cairn