manifest.json

{
    "name": "__MSG_appName__",
    "default_locale": "en",
    "version": "1.5",
    "description": "__MSG_appDesc__",
    "permissions": [
        "storage"
    ],
    "content_scripts": [
        {
            "run_at": "document_start",
            "matches": [
                "https://web.whatsapp.com/"
            ],
            "js": [
                "libraries/jquery.js",
                "libraries/arrive.js",
                "setBackground.js"
            ]
        }
    ],
    "action": {
        "default_popup": "popup.html",
        "default_icon": {
            "16": "images/icon16.png",
            "32": "images/icon32.png",
            "48": "images/icon48.png",
            "128": "images/icon128.png"
        }
    },
    "icons": {
        "16": "images/icon16.png",
        "32": "images/icon32.png",
        "48": "images/icon48.png",
        "128": "images/icon128.png"
    },
    "manifest_version": 3
}