Examine source code of Pocket Utility V2

{
  "manifest_version": 2,
  "name": "Pocket Utility V2",
  "version": "1.3",
  "description": "Save the current tab to Pocket quickly and easily.",
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/logo_64.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{41ffd90c-37e2-41c1-bc99-f59023984cb5}"
    }
  }
}