Launching today

Cairn — a companion for cancer treatment
A companion for cancer treatment, and the person beside you
2 followers
A companion for cancer treatment, and the person beside you
2 followers
Cairn keeps the ordinary things between cancer appointments — mood, reminders, calendar, a private journal — and lets the patient choose, switch by switch, what the person beside them can see. Plus a companion for 3AM, with limits it never crosses.






Hi Product Hunt — I'm Farzad, and I built Cairn.
My mom had cancer. On a day she wasn't feeling OK, I missed a phone call, and with it my last chance to visit her. That was the worst day of my life. I built Cairn so the people who love someone in treatment know when things aren't OK, even when nobody says it out loud, and so there's someone to talk to at 3am, when it's hardest.
It works on one idea: you might not want your sister reading your journal, but you do want her to know when you've had a bad week. So sharing works switch by switch. Turn one off and it disappears from your companion's screen immediately, and they aren't told what you hid.
The demo at cairnai.de is the real app with an invented week in it. Try the three roles at the top (the patient, her sister, her oncologist) and flip a sharing switch to watch the other screens change. You get five messages with the companion.
What it won't do matters as much. It won't give doses, read results or guess at survival odds. Those questions get the same fixed answer every time, set in code and never improvised by the model.
Two questions for you:
If you've been a patient or a carer: what did you wish someone else could see, without you having to say it?
If you're a clinician: would a flag like the one on Dr Vogel's screen help, or add noise?
We're raising a small pre-seed round. If that's relevant to you, there's an "I'm an investor" option on the site.