Examine source code of Beacon

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "32": "icon-32.png"
    }
  },
  "description": "Generate a report from Beacon (digitalbeacon.co) with a single click",
  "icons": {
    "128": "icon-128.png"
  },
  "manifest_version": 2,
  "minimum_chrome_version": "66",
  "name": "Beacon",
  "permissions": [
    "activeTab"
  ],
  "version": "1",
  "web_accessible_resources": []
}