Examine source code of Budget Manager

{
  "manifest_version": 2,
  "name": "Budget Manager",
  "description": "This extension tracks your overall spendings.",
  "version": "1.0",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_icon": "icon16.png",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "eventPage.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "notifications",
    "contextMenus"
  ],
  "options_page": "options.html",
  "browser_specific_settings": {
    "gecko": {
      "id": "{054fb29e-4f8f-4d92-85d7-c56cdbd1492d}"
    }
  }
}