Boules is a simple demo project. The goal was to build a puzzle game which could be installed as a desktop application, but also available as a web app (specifically a PWA).
The web app is implemented in React.js. The desktop version is an Electron app that wraps the React app. Also, the web app is a fully-fledged PWA (Progressive Web App). As a PWA, it is installable and live on the user's home screen, without the need for an app store.