Examine source code of EuroClix Clix Assistent

{
  "manifest_version": 2,
  "name": "EuroClix Clix Assistent",
  "version": "1.3.4",
  "default_locale": "nl",
  "description": "__MSG_extDescr__",
  "homepage_url": "https://www.euroclix.nl/",
  "applications": {
    "gecko": {
      "id": "@clixassistent",
      "strict_min_version": "50.0"
    }
  },
  "background": {
    "page": "background.html"
  },
  "page_action": {
    "default_icon": "icons/actions/icon-non-active.png",
    "default_title": "EuroClix Clix Assistent",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "http://*/*",
    "https://*/*",
    "activeTab",
    "tabs",
    "notifications",
    "contextMenus",
    "webNavigation",
    "webRequest",
    "webRequestBlocking",
    "unlimitedStorage",
    "storage",
    "background"
  ],
  "web_accessible_resources": [
    "toolbar.html",
    "style.css"
  ]
}