Hi there!

My name is Koen van Gilst and I'm a JavaScript developer who loves creating funny Twitter bots, educational games for my kids other creative stuff.

Have a look at my profile if you're interested in working with me. Or else feel free to browse through my experiments, projects and tutorials below.

You can also find me on Github, LinkedIn and Twitter. Or send me an email.

Have fun!

Peter and the Wolf

I created this PWA for my kids, based upon the classical piece "Peter and the Wolf" by Prokofiev. Turns out that making large mp3s available offline was harder than I thought.

Play + Source [2018]

Finding Nora

I created this fun little PWA for my daughter Nora to help her spell her name. She loved it, hope you do too!

  • 🚀 create-react-app + TypeScript
  • ⛺ full offline support
  • 🎺 web audio for sounds
Play + Source [2018]

MyTommy Loyalty App

For Tommy Hilfiger I worked in a Scrum team as a fullstack JavaScript developer on their loyality app MyTommy.

Demo page (in Dutch) [2018]

Audio Books Player

For Dedicon I created a player for their audio books collections, it's designed specifically for users with visual impairments. The player also has a karaoke function that highlights the text currently being read for children with dyslexia.

Demo page (in Dutch) [2017]

Star Wars or Star Trek?

Why not both? Using just CSS and a bit of JavaScript I recreated these classic science fiction intro's.

Star Trek + Source
Star Wars + Source [2017]

Shortcut Trainer

Quickly learn the 10 most commonly used keyboard shortcuts for the translation CAT tool MemoQ. Weekend project using React.

Demo + Source [2016]

LaTeX Letters

Creating beautiful PDF letters using LaTeX in a Docker container on a server.

Source code [2016]

Rush hour timelapse

A Twitter bot that creates daily timelapse videos of the traffic jams in The Netherlands. No longer active, but you can still see some of the old timelapses.

@altijdfiles + Source [2016]

Term Search

A terminology search engine for translators. Currently only German-Dutch terms. Work in progress. [ No longer online ]

Technologies: NodeJS, Express, MongoDB, Loopback, ReactJS.

Source [2016]

Help Terence!

A Twitter bot raising emoji money for his trip around the world. Fun little experiment with social media and Twitter bots. [ No longer active ]

Technologies used: Express, MongoDB.

@helpTerence + Source [2016]

Word to Line Prices

A simple web app for translators that converts a price per word to a price per standard line (55 characters).

Visit the app + Source [2016]

Wikipedia edits by the Dutch government

Twitter bot inspired by @congressedits that monitors and Tweets any edits made to Wikipedia by the Dutch government.

@OverheidEdits + Source [2013]


I once wrote this program in assembly, but this time I wanted to do it in Javascript.

Demo [2013]

Dawkins' Trees

For this web app I've tried to recreate (in part) the program Richard Dawkins describes in his book The Blind Watchmaker.

Demo [2013]