Examine source code of Bookmark Cycler

{
  "manifest_version": 2,
  "name": "Bookmark Cycler",
  "version": "1.2",
  "description": "Go through the bookmarks in the bookmarks toolbar when you click on button",
  "icons": {
    "48": "icons/bookmark-it.png",
    "96": "icons/bookmark-it@2x.png"
  },
  "permissions": [
    "bookmarks",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/star-filled-38.png",
    "default_title": "Bookmark Cycler"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{07417af6-1f90-419c-af37-c6b6417fdba0}"
    }
  }
}