Pfanda
A Pfand tracker that started as a joke on a walk home, and turned into my first real vibe-coded app.
The story
Four months after moving to Munich, I was walking through the Englischer Garten, watching people leave bottles by the trash cans instead of returning them for the deposit. I joked to myself — what if I tracked how much money was just sitting there. That joke didn't really go away, so in June 2025 I started building it. For an extra challenge, I built the entire thing in German, despite not really speaking German very well at the time.
It started as a single weekend project and then became an on-and-off thing I'd pick up in spare time over the following months. I ended up with a fully functioning native mobile app — receipt scanning to log your Pfand returns, a running calculator of euros recovered, gamification, social features so you could see friends' progress, and a set of panda personas and avatars I designed for the app's identity.
What I'm proud of
The receipt scanning was the hardest technical problem to solve, and getting it working was genuinely satisfying. But the part I loved most was designing the panda personas — and, for what it's worth, they were also the part that got the most unprompted enthusiasm from actual humans, including on dating apps, where "wait, you built an app with cute panda characters that tracks bottle deposits?" turned out to be a surprisingly good icebreaker. Not exactly rigorous product validation, but a nice reminder that the idea had charm.
Why it stalled
Momentum faded, honestly. I never found enough test users to justify a real Google Play Store launch, and a launch post I tried on r/pfand didn't land the way I'd hoped.
Lessons learned
- I should have found target users first and shown them the app live, in person, at the Pfandrückgabe machine — no App Store needed to test real interest.
- I never fully decided what Pfanda was for. For some people it could've been a genuinely useful way to track earnings; for others it was more of a silly, fun way to make a boring task less boring. Both are valid, but I never picked a lane.
- It never launched. But it's still the best app name I've ever come up with, and it's the project that started all of this — so it holds a pretty special place regardless.