Examine source code of Pullbucket

{
  "manifest_version": 2,
  "name": "Pullbucket",
  "version": "0.1.4",
  "description": "Pullbucket extension for Bitbucket",
  "icons": {
    "192": "logo192.png",
    "512": "logo512.png"
  },
  "browser_action": {
    "default_icon": "logo192.png",
    "default_title": "Pullbucket",
    "default_popup": "index.html",
    "theme_icons": [
      {
        "dark": "logo192.png",
        "light": "light192.svg",
        "size": 16
      },
      {
        "dark": "logo192.png",
        "light": "light192.svg",
        "size": 32
      }
    ]
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "notifications",
    "storage",
    "cookies",
    "https://app.pullbucket.com/"
  ]
}