Cairn

A note attached to a place, which surfaces itself when you arrive.

How to read a cairn

One stone for every thing to do

Start a line with - and it becomes a stone you can tick off. A note with four things to do is a cairn of four stones.

A ticked item is a hollow stone

You took it with you.

An empty cairn stays quiet

When every stone is hollow there is nothing left to say, so the note will not interrupt you. Untick something to wake it.

Warm means near

Stones brighten as you approach, and glow when you have arrived.

My note did not fire

Cairn tells you why. Nothing is hidden. In order of how often it turns out to be the cause:

• Location access is not set to “Always”. Cairn can only notice that you have arrived while it is closed if iOS lets it. Settings → Cairn → Location → Always.
• Every stone is hollow. A spent cairn is silent by design. Open the note and untick something.
• You dismissed it this visit. “Done this visit” and “Next visit” both stay quiet until you have actually left the place — a timer cannot know whether you are still in the shop.
• It is inside its cooldown. Ninety minutes by default, adjustable per note, so it does not nag while you wander near the edge.
• The radius is too small. Below about 100 metres the phone’s own position error is larger than the region. 150 m is the default for a reason.
• Quiet hours.
• You set it to fire once and it already has, so it archived itself.

Arrival is not instant. iOS deliberately waits before confirming you have crossed a boundary, so expect roughly twenty to thirty seconds.

Why does it want background location?

Because that is the whole product. A note that could only reach you when you already happened to be looking at your phone would not be worth writing. Cairn uses your location to notice arrivals and for nothing else, and it never sends it anywhere. See Privacy.

Get in touch

Questions, bugs, or ideas: ptgh@mac.com. A real person reads every one.

If you would rather raise it in the open, you can open an issue instead.