Examine source code of BGM Refresher

{
  "manifest_version": 2,
  "name": "BGM Refresher",
  "version": "1.1",
  "description": "",
  "icons": {
    "48": "images/logo48.png"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": "images/logo48.png",
    "default_title": "BGM Refresher",
    "default_popup": "popup/popup.html"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab",
    "storage"
  ]
}