Examine source code of Platan Click2Call

{
  "applications": {
    "gecko": {
      "id": "click2dial@platan",
      "strict_min_version": "57.0"
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon16x16.png",
      "48": "images/icon48x48.png"
    },
    "default_title": "Platan Click2Call",
    "browser_style": false,
    "default_popup": "popup.html"
  },
  "name": "Platan Click2Call",
  "author": "Platan Sp. z o.o sp.k",
  "description": "Aktywuje funkcję Click To Call. Kliknij numer na stronie www, by zadzwonić przez serwer Platan.\nAdres strony: www.platan.pl",
  "version": "1.0.0",
  "manifest_version": 2,
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "contextMenus",
    "http://*/*",
    "https://*/*",
    "notifications"
  ],
  "background": {
    "scripts": [
      "js/background.js",
      "js/call-handler.js",
      "js/jquery.min.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "js": [
        "js/libphonenumber-js.min.js",
        "js/app.js",
        "js/validation.js",
        "js/call-handler.js",
        "js/jquery.min.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_idle",
      "exclude_globs": [
        "*youtube*",
        "*server_log*"
      ]
    }
  ],
  "web_accessible_resources": [
    "images/icon64x64.png"
  ],
  "icons": {
    "16": "images/icon16x16.png",
    "48": "images/icon48x48.png",
    "128": "images/icon128x128.png"
  }
}