Cairn collects nothing. There is no account, no server, and nowhere for your data to go.
That is the entire policy. The rest of this page explains it precisely, because “we value your privacy” is what every app says and none of it is checkable.
Your notes, the places you attach them to, the radius you chose, what you have ticked off, and the record of when a note last fired. All of it is stored on your iPhone and nowhere else. It is not uploaded, backed up to a server we run, or synchronised through us, because there is no “us” in the loop — Cairn has no server.
If you have iCloud Backup switched on, your device backup is handled by Apple under Apple’s terms. That is between you and Apple; we never see it.
Cairn asks for location access so it can notice that you have arrived somewhere, including while the app is closed. That is what the product does.
Your location is read by your iPhone, compared against the places you saved, and discarded. That is how Cairn notices you have arrived, and it happens entirely on the phone. Your location is never transmitted to us. It reaches Apple Maps while you are leaving a note or picking a note’s place again, and what3words only if you open a place there, both described below. We could not look up where you have been even if we wanted to, and no request from anyone could make us produce it.
Being exact about this matters more than sounding clean. There are five things, and each happens only while you are using the part of Cairn that needs it.
Leaving a note, or picking its place again. The screen for leaving a note uses Apple Maps, through Apple’s own MapKit framework, as soon as it opens: to draw the map, to show the address of the spot where the note is pinned, and to list places near you. For that, Apple receives the pinned spot, where you are, and the area on screen. If you search for a place by name, what you typed goes to Apple Maps too, with a rough area to search within. These requests are handled by Apple, governed by Apple’s Privacy Policy, and their results come straight back to your phone. We do not receive them, store them, or have any means of accessing them.
Editing a cairn you made yourself offers “Pick the place again”, and a place with several cairns offers “Leave another note here”. Both open the same list. Nothing is sent until you tap one. When you do, Apple receives the same kinds of thing, except that the pinned spot is the cairn’s or the place’s position, which may be nowhere near you.
Directions to a cairn. Every cairn offers walking directions. Nothing happens until you tap them. When you do, Cairn hands that cairn’s place and position to Apple Maps, which opens with walking directions from where you are. Apple receives the place and your location, exactly as it would for any route you asked it for. The request is handled by Apple, governed by Apple’s Privacy Policy, and its result comes straight back to your phone. We do not receive it, store it, or have any means of accessing it.
Opening a place's app. When a cairn was made from a place Apple Maps knows, and that place has its own website, a long press offers to open the place’s app. Nothing happens until you choose it. When you do, Cairn hands that website’s address to iOS, which opens the app the place has linked to it — if you have it installed. If you don’t, nothing opens. Cairn contacts no one itself and receives nothing back.
Open in what3words. This is off unless you turn it on in Cairn’s About screen. When it is on and you tap “Open in what3words” on a place, Cairn opens what3words’ own website or app at that place’s coordinates. The coordinates reach what3words in that link, because you chose to open it. Cairn itself never contacts what3words and receives nothing back. What happens after that is governed by what3words’ privacy policy.
Sharing cairns. When you tap Send in SHARE, the cairns you switched on (each one’s place name, where it is, its radius, its words and when it should surface) are put inside a link, with your name if you gave one in YOU. The link goes wherever you send it: Messages, Mail or any other app you pick, and that app carries it under its own terms. Some encrypt messages end to end; many do not. The cairns travel after the “#” in the link, a part that browsers never send to a website, so they never reach us, or GitHub, which hosts the page the link opens. Anyone who has the link can see those cairns, so send it only to people you would tell.
Apart from these five, nothing leaves your device.
Asking about your cairns. Where Apple Intelligence is switched on, YOU offers “Ask about your cairns”. Its answers come from Apple’s language model running on this iPhone: your question and the cairns it reads stay on the device, and nothing is sent to Apple or to us. Neither your question nor its answer is kept.
The notifications Cairn sends are created on your device at the moment they are needed. They are not pushed from a server, and their contents — the place, the note, the items left — never travel anywhere.
Under the UK GDPR and equivalent laws you have rights to access, correct, export and erase personal data held about you. We hold none, so there is nothing for us to produce or delete. Your own copy is on your phone: deleting a note deletes it, and deleting Cairn removes everything it ever stored.
Cairn is suitable for all ages and collects no data from anyone, regardless of age.
If Cairn ever collects anything, this page will say so plainly and in advance, and the App Store privacy label will be updated to match before the version that does it ships.
Anything about privacy, or this page: ptgh@mac.com