Examine source code of mDNS Discover

// -*- Espresso -*-
{
    "browser_specific_settings": {
        "gecko" : {
            "id": "mdns@exmaple.com"
        }
    },
    "name": "mDNS Discover",
    "version": "0.4",
    "manifest_version": 2,
    "description": "Dynamically discover local servers and devices using Multicast DNS.",
    "background": {
        "scripts": ["background.js"]
    },
    "browser_action": {
        "browser_style": true,
        "default_icon": "radio.svg",
        "default_popup": "popup.html",
        "default_title": "mDNS Discover",
        "theme_icons": [{
            "dark": "radio-dark.svg",
            "light": "radio.svg",
            "size": 16
        }]
    },
    "icons": {
        "16": "radio-dark.svg"
        // , "48": "radio-dark.svg"
        // , "128": "radio-dark.svg"
    },

    "options_ui": {
        "browser_style": true,
        "page": "options.html"
    },
    "permissions": [
        "nativeMessaging",
        "notifications",
        "storage"
    ]
}