Examine source code of Image Picker

{
  "manifest_version": 2,
  "name": "Image Picker",
  "version": "1.0",
  "description": "Téléchargez toutes les images d'une page web",
  "permissions": [
    "downloads",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2700a927-cfe1-4b20-a167-59001746cd11}"
    }
  }
}