Examine source code of Subscrybe

{
  "name": "Subscrybe",
  "version": "1.0.3",
  "description": "Manage subscriptions, and get alerted before next billing date.",
  "manifest_version": 2,
  "permissions": [
    "https://my.subscrybe.app/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Subscrybe",
    "default_icon": "subscrybeIcon.png"
  }
}