Web App Manifest

A JSON file that tells browsers how to install and display a web app, app name, icons, start URL, display mode (standalone = no browser bar), and theme colours.

The web app manifest is what turns a website into an installable PWA. Without it, the "Add to Home Screen" feature doesn't work and the app opens in a browser rather than its own window.

A founder's app has a manifest.json specifying its name, a brand theme colour, and display: standalone. Users who install it from Chrome see it open in its own window, like a native app.