Support Cailloux
The app is free, with no advertising and no ad trackers. It will stay that way. But it runs on servers, and servers cost money.
What a tip pays for
Nothing abstract, and nothing that goes into my pocket. These are the costs that keep Cailloux running:
- Hosting for the apps — the tracking app, Le Cairn, the website.
- The live database: every check-in, every pebble, every alert goes through it. This is the cost that grows with the number of runners.
- The emails — forgotten passwords, the race report to the route planner.
- The domain name cailloux.app, and the certificates that go with it.
In plain terms: your tip pays for part of the server that will carry the tracking of somebody's next race. That is all it does, and it is already a great deal.
* How that is worked out
The figure rests on 4 assumptions, stated here so anyone can judge them: a 100 km race, followed live by 100 people, at a rate of 50 races a month, and assuming the database's free megabytes are already used up — the least favourable case.
What is left of €1
| Your donation | €1.00 |
| Tipeee commission (8%) | − €0.08 |
| Payment fees (1%) | − €0.01 |
| Received by Cailloux | €0.91 |
What a 100 km race costs
| Live data — 89 MB at €0.86/GB | €0.08 |
| Share of the servers — €12.58/month ÷ 50 races | €0.25 |
| Total | €0.33 |
€0.91 ÷ €0.33 × 100 km = 277 km. The volumes are measured on a real race: 0.85 MB per person following a whole race, 0.14 MB per member of the support crew, and around 4 MB to prepare the race in Le Cairn.
And because leaving it out would be dishonest: the database costs nothing today — traffic stays below the free threshold. What actually gets paid for is the servers and the domain name, about €151 a year, whether there is one race or a thousand. Your euro pays for that first.
Why I do not charge for the app
Cailloux was born out of one race: I wanted my family to know where I was across 78 km of trails, without paying a subscription, without creating 10 accounts, without handing our data to anyone.
Charging for the app would betray the very thing it came from. And a crew waiting for a runner at night should never hit a paywall — following someone you love through a race is not a premium service.
I build Cailloux alone, in my spare time. The time, I give gladly. It is the bills that cannot be given away.
What your support does not change
Best said up front, so that nobody gives thinking they are buying something:
- No feature reserved for supporters. Everyone has the same app, with everything in it.
- One exception, and it unlocks nothing: a sticker, for anyone who supports at €50. It goes on a water bottle, and that is all it does — and it can be earned by running too: the first 30 people to actually run with Cailloux get one, without giving anything. So supporting does not even buy you that exclusively.
- No advertising will replace tips if there are none — that is a choice, not a lack of offers.
- No data sold, ever. Not the tracks, not the phone numbers, not the addresses. It is written in black and white on the privacy page.
- No obligation, and no reminders: Cailloux will never ask you to support it from inside the app, during a race or after one.
A donation buys you no feature: it pays for the server. In other words, you are paying in advance for other people's races — a stranger's, next month, whom you will never see go by. Solidarity between trail runners, not a subscription.
One-off or monthly, from 1 €, cancellable at any time. Tipeee is a French platform — it handles the payment, and Cailloux never sees your card details.