Daniel Kloosterboer

Useful software, carefully made.

A former auditor building real, working software with AI coding agents. Several pieces are live, and you can try them now.

Explore the workTry one now

01Featured

Built, shipped and in use.

chirputilities.com
Chirp Utilities homepage: “Utility billing, without the guesswork.” beside a sample portfolio card listing four properties and their bill statuses
A finalized $229.14 water bill for a sample property, split across five units with a $0.00 difference

Chirp Utilities

Utility billing for property managers, where every dollar reconciles to the cent.

Built for businessLive website
  • Every dollar accounted forEvery change logged, with who made it and why.
  • Flexible bill splittingBy unit, occupants, square footage or usage.
  • AI-assisted bill readingA person confirms anything it isn't sure of.
Visit Chirp Utilities (opens in a new tab)Read the case study
budget-demo.daniel-kloosterboer.chatgpt.site
Budget overview in the dark theme for a fictional demo household: total debt, monthly spending, income and net cash flow cards with sparklines, above a “Where it went” bar chart
The money map in galaxy view: payees drawn as linked circles sized by spend, fictional demo data

Household Budget

A clickable household budget with debt history, smart rules and a money map.

Built for everyday lifeInteractive demo
  • Spending insightsEvery total opens up to the transactions behind it.
  • Debt trackingBalance history with limits and interest estimates.
  • Interactive money mapFollow each dollar from income to payee.
Try the demo: Household Budget (opens in a new tab)Read the case study

Fictional data

Live storefront · digital library

Luna Mysteries

Murder-mystery party kits, with a library that casts your guests and prints their names.

The hard part of hosting a murder-mystery party is casting it. Luna’s library does the casting: one link for the guests, and documents that follow the host’s choices.

Visit Luna Mysteries (opens in a new tab)Read the case study

02Try it now

Try it yourself.

The real apps, running on fictional data. No sign-in.

03All work

Everything else I’ve built.

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04How I work

Trained to doubt the numbers.

Before software I worked in audit and financial analysis: don’t trust a figure until you can trace it, and find the manual work hiding inside a process.

I build the same way with AI. The agents write much of the code; I decide what gets built, set the rules, read the changes and make the tests prove it.

More about me