Examine source code of Bookmark Manager

{
  "manifest_version": 2,
  "name": "Bookmark Manager",
  "version": "1.2.2",
  "icons": {
    "16": "icon-16x16.png",
    "32": "icon-32x32.png",
    "48": "icon-48x48.png",
    "96": "icon-96x96.png",
    "128": "icon-128x128.png"
  },
  "browser_action": {
    "default_icon": "icon-48x48.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Alt+B",
        "mac": "MacCtrl+Command+B"
      }
    }
  },
  "background": {
    "scripts": [
      "assets/background.js"
    ]
  },
  "permissions": [
    "bookmarks",
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f5197d2b-302b-4ffe-b73c-b397dc22a5b7}"
    }
  }
}