Examine source code of Toggle Images

{
  "manifest_version": 2,
  "name": "Toggle Images",
  "version": "1.0",
  "description": "Toggle visibility of all images on the page.",
  "browser_action": {
    "default_title": "Toggle Images",
    "default_icon": {
      "64": "icon64.png",
      "128": "icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f2787671-8f56-4473-bc09-26dcf05472d7}",
      "strict_min_version": "115.0"
    }
  }
}