Custom Development

crypto-dash.grn.dk is the public window onto a strategy-research rig that runs on our own server and trains itself. Every hour it backtests a fresh batch of trading-strategy configurations against five-minute crypto candles, scores each one on data it was not fitted to, keeps a running leaderboard, promotes the configurations that hold the top into a simulated book, and demotes them again as soon as their forward behaviour drifts away from what the backtest promised.

It is paper trading only. The installation holds no exchange keys, calls no order endpoint and has no account to spend from. Every fill, every position and every P&L figure on that page is simulated — which is why the page prints PAPER ONLY on itself, in orange, at the top of every hourly regeneration.

veganpower.grn.dk is Vegan Power, a catch-the-fruit arcade game with a rule you understand in one second: eat fruit, not friends. Fruit falls and you catch it. A chicken, a cow or a penguin falls and you dodge it — each one you hit costs one of your seven hearts. It began in 2020 as a small Flutter and Flame game for Android, released on Google Play that December. In 2026 it was taken apart and rebuilt: it now opens in any browser with no install and no account, keeps a global high-score table on its own small API, and carries a multiplayer beta where two to four players share one arena and shove each other off the fruit.

fantasy.grn.dk is コトバモン KotobaMon — a 3D monster-catching game that runs in an ordinary browser tab, where every monster is a Japanese word. ヒバナ hibana is a spark, コダマ kodama is a tree spirit, and catching one is how the word gets learned. It has a procedurally generated island with five biomes, twelve species, turn-based battles with a type chart, and full Japanese voice-over subtitled in Japanese, romaji and English at the same time. There is no download, no account, no build step and no backend: the whole game is 2,821 lines of vanilla JavaScript plus a vendored copy of Three.js, served as static files.

abc.grn.dk teaches a child to write an alphabet rather than to recognise one: pick a letter, trace it with a finger, and the app scores the shape you actually drew and tells you how close you got. Thai first — all 44 consonants, free — with Japanese hiragana and katakana behind a premium gate. Everything happens in the browser: the handwriting recogniser is plain Dart running on the device, the spoken letter names are files bundled with the app, and there is no account, no runtime backend and no advertising.

A Danish coworking space wanted members to book a table by the hour and pay for it — because at 20 kr. per hour per table, a booking that has not been paid for is not a booking. tableflow.grn.dk is that system, built from the client's brief and running live: an hour grid that shows what is actually free, a fifteen-minute payment hold that releases itself, and an admin screen for the people who run the place. Plain PHP and MariaDB — no framework, no dependencies, 853 lines in seven files.