Examine source code of Scroll End Indicator

{
  "manifest_version": 2,
  "name": "Scroll End Indicator",
  "version": "1.0",
  "description": "Shows a small notification when you scroll to the end of a webpage.",
  "permissions": [
    "tabs",
    "activeTab",
    "storage"
  ],
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon48.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1ed4d0df-51a8-44cc-bc29-19e45c4d23cc}"
    }
  }
}