Examine source code of simplyscroll

{
  "manifest_version": 2,
  "name": "SimplyScroll",
  "version": "0.1",
  "applications": {
    "gecko": {
      "id": "simplyscroll@ryse.top"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Setup",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "app.js"
      ],
      "css": [
        "app.css"
      ]
    }
  ],
  "icons": {
    "32": "auto-scroll.svg"
  },
  "web_accessible_resources": [
    "auto-scroll.svg"
  ]
}