Examine source code of Text Modifier

{
  "manifest_version": 2,
  "name": "Text Modifier",
  "version": "1.0",
  "description": "Change text color and size on any webpage.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "widget.js"
      ],
      "css": [
        "widget.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6c616888-fb42-46bd-8020-b0a6158aa3e2}"
    }
  }
}