Examine source code of Save web to Pocket

{
  "manifest_version": 2,
  "name": "Save to Pocket",
  "version": "1.0",
  "description": "Save the current page to your Pocket-style list.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Save to Pocket"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4c683249-535c-4e63-bba2-db2cbc959c80}"
    }
  }
}