Examine source code of ClearInput

{
  "manifest_version": 2,
  "name": "ClearInput",
  "version": "1.3",
  "description": "Place a clear input box on all input fields",
  "icons": {
    "64": "icons/ClearInput-64.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "jquery-3.2.1.min.js",
        "ClearInput.js"
      ],
      "css": [
        "ClearInput.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{50580d21-0023-4891-bc1b-d2a1b898449c}"
    }
  }
}