Mostly entirely vibe-coded experiments, self-hosted where possible, always mobile-friendly. Everything below is a single static HTML file.
Roman numerals for a seven-year-old. First the explainer, with a slider that translates any number up to 100 and shows how XLVII is built. Then five levels of games: crack the code carved on a stone vault, chisel a number into your own tablet, and solve sums written in Roman numerals — never crossing a ten. In Dutch, touch-friendly.
Speed maths for a seven-year-old: every correct sum hops the frog one lily pad, a full crossing unlocks a harder level. Starts at 7 + 2, climbs to 24 + 36 and 60 + ? = 100, never past 100. Two minutes, points for being fast, a personal record. In Dutch, touch-friendly.
Ten hard sums up to 100 for a seven-year-old: every one crosses a ten, so 24 + 36 and 82 − 37 rather than easy plusses. Splitting hints, stars, a personal record. In Dutch, touch-friendly.
What is a bank, explained to a seven-year-old in nine interactive steps: marbles become money, the vault hands out paper promises, and you watch a bank run empty the safe. In Dutch.
A kid-friendly Minesweeper with a garden-digging theme. Dig in the grass, plant flags, and watch out for the bombs. In Dutch, touch-friendly, works offline.
Interactive timeline of every major model release from Anthropic, OpenAI, Google DeepMind, and xAI — watch the pace accelerate.
Interactive 3D celestial sphere showing all 88 constellations, zodiac positions, and visible sky based on date and latitude.
Interactive mandala showing real-time planet positions mapped to the zodiac and the 64 I Ching gates with search and gate highlighting.
Interactive 3D and 2D visualization of the 26,000-year axial precession cycle and the astrological ages.
Rapid Serial Visual Presentation reader that displays text one word at a time with adjustable speed and optimal recognition point highlighting.
Interactive ASRS-5 screener that walks you through six research-backed questions with instant scoring and guidance.
Compare cities side-by-side with detailed metrics, data visualizations, and insights to help inform your next move.
Visualize the power of compound interest over time with interactive charts and detailed yearly breakdowns.
Compare and explore alternative keyboard layouts beyond QWERTY. Interactive rankings with ergonomic metrics and community resources.