Examine source code of Bookmark Usage Checker

{
  "manifest_version": 2,
  "name": "Bookmark Usage Checker",
  "version": "1.3",
  "description": "Checks how many times your bookmarked sites have been used.",
  "icons": {
    "48": "icons/logo.png"
  },
  "permissions": [
    "bookmarks",
    "history"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/logo.png",
    "default_title": "Bookmark Usage Checker"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{63ad1a94-9b30-45e7-80e3-b137406075d2}"
    }
  }
}