Examine source code of Pensive

{
  "manifest_version": 2,
  "name": "Pensive: Save & Search What You Read",
  "short_name": "Pensive",
  "version": "0.4.10",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "description": "Save the best of what you read online and build your own searchable memory of the web",
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "<all_urls>",
    "https://getpensive.com/*"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_action": {
    "default_title": "Pensive - Save this page",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_page": "options.html",
  "content_scripts": [
    {
      "matches": [
        "https://getpensive.com/extension/auth"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "options.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "pensive-extension@getpensive.com",
      "data_collection_permissions": {
        "required": [
          "browsingActivity"
        ],
        "optional": [
          "websiteContent"
        ]
      }
    }
  }
}