Examine source code of FingerKey

{
  "description": "Login to websites using your phone's biometric authentication. Install FingerKey on your phone and your computer in order to use the extension.",
  "manifest_version": 2,
  "name": "FingerKey",
  "version": "1.4resigned1",
  "icons": {
    "16": "./icon-16.png",
    "32": "./icon-32.png",
    "128": "./icon-128.png"
  },
  "applications": {
    "gecko": {
      "id": "fingerkey@mozilla.org",
      "strict_min_version": "46.0"
    }
  },
  "permissions": [
    "notifications"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/lib/jquery-2.2.0.js",
        "js/InterfaceUtils.js",
        "js/WindowMessages.js",
        "js/DataReceivers.js",
        "js/HtmlParse.js",
        "js/InjectUserAndPassword.js",
        "js/lib/bililiteRange.js",
        "js/lib/jquery.sendkeys.js",
        "js/SetupPasswordField.js",
        "js/SetupNameField.js",
        "js/Init.js"
      ],
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "images/16.png",
    "images/32.png",
    "images/avatar.png",
    "images/FingerPrint.svg",
    "images/Pencil.svg",
    "css/style.css"
  ]
}