From bottles carried to the shop to an app that keeps track of your vouchers.
It all started quite ordinarily: in February 2026, with carrying deposit bottles to the nearby shop.
We did it as part of our household chores. There were two of us, me and my neighbour. We weren’t thinking about any app back then. We returned the bottles, got vouchers for them, and spent those vouchers on a bottle of Coca-Cola. For us it was a kind of money of our own.
After a while, just carrying bottles stopped being enough. We started competing: who collects more, who gets the better score. Other friends quickly joined, and two people turned into a bigger crew.
To give the competition some rules, I built a simple website where we logged our vouchers and scores.
The more bottles we returned, the more paper deposit vouchers we got. And then we stopped spending them right away. We preferred to collect bigger sums and save up for mini LEGO sets rather than trade everything in for Cokes as we went.
There was just one problem. A paper voucher in your pocket is a voucher that got lost and eventually expired.
A few months later, over the summer, I wanted to find out, before university, whether economics and business really interested me. It mattered to me to dig deeper through a real project: learn something from it and see whether I could handle it and whether I enjoyed it.
Kappka was just a simple website back then, but I had come to like the idea of competition. The problem with vouchers that got lost and expired was getting annoying. I decided to return to that idea and take it on seriously, as my very own first project.
The website worked, but it had one huge flaw: every code had to be typed in by hand. With a few vouchers that was bearable. With a dozen or more, it wasn’t.
That’s when I started on the first version of what is now Kappka. I had never built an app before, so I started from scratch, with the help of AI. After a few months of work, version by version, I turned the website into an app and added scanning.
Now you just scan the voucher, and the voucher ends up in the app instead of in your pocket. And at the checkout you can redeem it straight from your phone, and Kappka will remind you before it expires. Everything counts towards the scores right away.
Kappka is still what it started as: collecting together, competing, and saving up for something you really want.
