Trond Wuellner, building in the open
I make things I actually want to use, then write down what worked, what broke, and what I would do differently. The apps are here. So are the mistakes.
Walk. Bake. Feed the duck.
A cozy bakery game that runs on your real steps. Walking earns ingredients, baking asks you to put the phone down, and Doug the duck runs the shop while you are away. Built because a number going up has never once got me out of the door, and owing a duck a bag of flour turns out to work rather better. Nothing leaves your phone.
Your whole trip, offline and private.
Itinerary, city guides, maps, currency, flights and documents in one app. Built because our family travel doc kept falling apart in exactly the places with no signal. No account, no tracking, your data stays yours.
Written about it
Build the travel app you've always wanted Jun 2026
A professional light meter, machined for iPhone.
Zone System metering, datasheet-accurate film stocks, Zeiss V-system lenses and a 16-bit Display P3 pipeline. I built it to force myself to understand light, not because the world needed another meter. No account. Nothing leaves your phone.
Turn a single photo into a 3D Gaussian splat.
A macOS app built on Apple's ml-sharp: convert one JPEG or PNG into a 3D Gaussian splat, pull depth and stereo pairs out of iPhone spatial photos, and fly around the result in a Metal renderer. I built it the week the model shipped, to understand how the technique actually works.
Written about it
Let's Build Rad Shit Together (where it first appears) Jan 2026
Worksheets whose every answer is proved before it prints.
Generates math worksheets and answer keys from counting through calculus, and checks each answer with SymPy before anything reaches paper. Drops into Claude Code, Gemini or Codex as one skill. I use it for my own kids, which is why the verifier is honest about what it cannot prove.
Written about it
One wild trick to help your kids with math Feb 2026
Give an AI agent a memory that lasts.
A knowledge graph that synthesises what an agent learns, finds connections between notes, and keeps context across sessions, so you stop re-explaining your project every time the conversation gets compacted.
Written about it
Agent Amnesia and Broken Data Models Feb 2026“I build things to figure out how they work.” Let's Build Rad Shit Together, December 2025
The app is rarely the goal. The understanding is. A darkroom class turned into a light meter; a family trip that kept breaking turned into a travel app. Some of it ships, some of it stays a side quest, and the part worth reading is usually what went wrong on the way.
I write at Build Rad Shit about making things, mostly where AI meets actually shipping something.
Everything here is local-first: it works offline, keeps your data on your device, and asks for as little as it can. Where an app syncs, it encrypts on the device first, so the server only ever holds a blob it cannot read. Alongside the apps there are trip guides, light meters, darkroom prints, gaussian splats, film scans, and a couple of apps I am building with my kids. Not all of it works. That part gets written down too.