Examine source code of Barkr

{
  "description": "Bookmarking app",
  "manifest_version": 2,
  "name": "Barkr",
  "version": "1.0",
  "homepage_url": "https://www.getbarkr.com",
  "icons": {
    "48": "icons/logo_full.png"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "cookies",
    "clipboardWrite",
    "https://app.getbarkr.com/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/logo_bw.png",
    "default_title": "Save bookmark",
    "default_popup": "popup/save_bookmark.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2680d586-7e4d-414e-8aa6-5f365fc6758c}"
    }
  }
}