Kilian Valkhof

Front-end & user experience developer, Jedi.

Notarizing your Electron application

Electron, 4 June 2019

Starting with MacOS 10.14.5, all signed applications by ‘new’ developers will also need to be notarized or they will trigger Apple’s Gatekeeper software and prevent users from installing your app. That means you will need to Notarize your Electron applications as well. This is how to successfully notarize your Electron application.

Polypane available now

Apps, 14 May 2019

Polypane is out today! Polypane is a browser for developers, designers and everyone else that creates websites and webapps. This release has been a long time in the making, and has taken a lot of hard work in the past months to get this release out the door. I am incredibly proud of the app I’ll be sharing with all of you today.

Getting Polypane ready for release

Apps, 30 April 2019

In a few weeks, Polypane version 1.0 will be released. In these past few months I’ve been hard at work getting everything ready for that release. 

The process has very little to do with the app itself and much more with creating the infrastructure around it. I thought it would be interesting to go through this to show you what it takes.

What it means to be a Firstversionist

Life, 23 April 2019

I want to tell you about my new company Firstversionist. But to do that, I also need to tell you a little more about me.

What design tools get wrong

Design, 8 April 2019

Modern design tools, of both the vector and code kind, are amazing pieces of software that in recent years have transformed the design profession, but none of them seem to really understand the context that we currently design for. The remnants of fixed-dimensions are still visible in all and the tools are not helping us with the considerations and trade-offs that designers have to make about their work. Here are some of the features that my ideal design tool would support natively.



A cross-platform browser for responsive web design and development.


A cross-platform, simple and smart autosaving scratchpad.


Drag-and-drop lossless compression of PNG and JPG images for web.

Messenger Demo Viewer

Demo your (bot) interactions on Messenger.



The latest Electron news, articles, apps and interviews.

A Messenger Adventure!

Go on a text adventure in Facebook Messenger.

Fuck Yeah Keming!

A celebration of horrendous kerning.

More projects

Head over to my Projects page for more.

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