Examine source code of Quick Save

{
  "manifest_version": 2,
  "name": "Quick Save",
  "version": "1.0",
  "description": "Quickly save screenshots and images to a specified folder.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "popup.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7eb82104-4131-4b58-998b-006b93ff08fa}"
    }
  }
}