Examine source code of PENI-

{
  "manifest_version": 2,
  "name": "PENI-",
  "version": "1.3.1",
  "description": "A new cutting-edge extension that will revolutionise the way you browse the internet, Forever.",
  "icons": {
    "170": "icon.jpg"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "common.js",
        "content.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "web_accessible_resources": [
    "icon.jpg"
  ],
  "browser_action": {
    "default_icon": "icon.jpg",
    "default_title": "PENI-",
    "default_popup": "popup/index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4fa42406-370f-48d1-a819-7754b579bc21}"
    }
  }
}