Examine source code of KnowNews

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDescription__",
  "version": "0.10.0",
  "short_name": "__MSG_appShortName__",
  "manifest_version": 2,
  "default_locale": "en",
  "browser_action": {
    "default_icon": "images/icon/icon.svg",
    "default_popup": "pages/popup.html",
    "default_title": "KnowNews"
  },
  "icons": {
    "16": "images/icon/icon.svg",
    "128": "images/icon/icon.svg"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "tabs",
    "notifications",
    "storage",
    "http://*/",
    "https://*/",
    "<all_urls>"
  ],
  "optional_permissions": [
    "notifications",
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "developer@assemble.co.za",
      "strict_min_version": "57.0"
    }
  }
}