Examine source code of URL Tooltip WE

{
  "default_locale": "en",
  "description": "__MSG_utwe_description__",
  "manifest_version": 2,
  "name": "__MSG_utwe_name__",
  "version": "0.9.4resigned1",
  "applications": {
    "gecko": {
      "id": "url-tooltip-we@ajitae.ru",
      "strict_min_version": "56.0"
    }
  },
  "author": "AjiTae",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png",
    "144": "icons/144.png",
    "192": "icons/192.png",
    "240": "icons/240.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start",
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "permissions": [
    "storage"
  ]
}