Examine source code of Safefly

{
  "default_locale": "en",
  "options_ui": {
    "page": "html/options.html",
    "open_in_tab": false
  },
  "content_scripts": [
    {
      "run_at": "document_start",
      "matches": [
        "*://www.ozon.travel/*",
        "*://www.anywayanyday.com/*",
        "*://biletix.ru/*",
        "*://www.aerobilet.ru/*",
        "*://www.svyaznoy.travel/*",
        "*://*.mytrip.com/*",
        "*://www.orbitz.com/*",
        "*://www.expedia.com/*",
        "*://www.pososhok.ru/*",
        "*://www.kupibilet.ru/*",
        "*://www.aviakassa.com/*",
        "*://avia.tickets.ua/*",
        "*://*.travelgenio.com/*",
        "*://go2see.ru/*",
        "*://*.edreams.com/*",
        "*://www.edreams.de/*",
        "*://www.edreams.es/*",
        "*://www.edreams.fr/*",
        "*://www.edreams.gr/*",
        "*://www.edreams.it/*",
        "*://www.edreams.pt/*",
        "*://www.edreams.com.ru/*",
        "*://www.edreams.ch/*",
        "*://www.edreams.com.tr/*",
        "*://www.edreams.co.uk/*",
        "*://www.edreams.com.ar/*",
        "*://www.edreams.com.br/*",
        "*://www.edreams.com.mx/*",
        "*://www.edreams.pe/*",
        "*://www.edreams.com.ve/*",
        "*://www.edreams.com.au/*",
        "*://www.edreams.hk/*",
        "*://www.edreams.in/*",
        "*://www.edreams.jp/*",
        "*://www.edreams.ph/*",
        "*://www.edreams.ma/*",
        "*://www.edreams.ae/*",
        "*://www.edreams.net/*",
        "*://www.supersaver.ru/*",
        "*://www.onetwotrip.com/*",
        "*://*.aeroflot.ru/*",
        "*://www.finnair.com/*",
        "*://*.lufthansa.com/*",
        "*://*.austrian.com/*",
        "*://www.turkishairlines.com/*",
        "*://www.swiss.com/*",
        "*://www.britishairways.com/*",
        "*://*.klm.com/*",
        "*://*.klm.ru/*",
        "*://www.virginatlantic.com/*",
        "*://*.airfrance.ru/*",
        "*://*.airfrance.us/*",
        "*://*.airfrance.com/*",
        "*://*.airfrance.co.uk/*",
        "*://*.airfrance.de/*",
        "*://*.airfrance.es/*",
        "*://*.airfrance.it/*",
        "*://*.airfrance.ua/*",
        "*://*.airfrance.pl/*",
        "*://*.s7.ru/*",
        "*://www.travelocity.com/*",
        "*://*.hotwire.com/*",
        "*://www.priceline.com/*",
        "*://www.cheapoair.com/*",
        "https://safefly.me/*"
      ],
      "css": [
        "html/styl/fonts.css",
        "html/styl/banner.css"
      ],
      "js": [
        "vendors.js",
        "config/_config.js",
        "contentScript.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "vendors.js",
      "config/_config.js",
      "vendor/autobahn.js",
      "backgroundScript.js"
    ]
  },
  "browser_action": {
    "default_title": "Safefly",
    "default_icon": {
      "16": "icons/default16.png",
      "48": "icons/default48.png",
      "128": "icons/default128.png"
    },
    "default_popup": "html/popup/unauthenticated.html"
  },
  "icons": {
    "16": "icons/default16.png",
    "48": "icons/default48.png",
    "128": "icons/default128.png"
  },
  "name": "Safefly",
  "version": "0.2.5",
  "description": "__MSG_appDescription__",
  "web_accessible_resources": [
    "html/vendor/fonts/*",
    "html/icons/banner/*.png",
    "vendors.js",
    "responseInjection.js"
  ],
  "permissions": [
    "*://www.ozon.travel/*",
    "*://www.anywayanyday.com/*",
    "*://biletix.ru/*",
    "*://www.aerobilet.ru/*",
    "*://www.svyaznoy.travel/*",
    "*://*.mytrip.com/*",
    "*://www.orbitz.com/*",
    "*://www.expedia.com/*",
    "*://www.pososhok.ru/*",
    "*://www.kupibilet.ru/*",
    "*://www.aviakassa.com/*",
    "*://avia.tickets.ua/*",
    "*://*.travelgenio.com/*",
    "*://go2see.ru/*",
    "*://*.edreams.com/*",
    "*://www.edreams.de/*",
    "*://www.edreams.es/*",
    "*://www.edreams.fr/*",
    "*://www.edreams.gr/*",
    "*://www.edreams.it/*",
    "*://www.edreams.pt/*",
    "*://www.edreams.com.ru/*",
    "*://www.edreams.ch/*",
    "*://www.edreams.com.tr/*",
    "*://www.edreams.co.uk/*",
    "*://www.edreams.com.ar/*",
    "*://www.edreams.com.br/*",
    "*://www.edreams.com.mx/*",
    "*://www.edreams.pe/*",
    "*://www.edreams.com.ve/*",
    "*://www.edreams.com.au/*",
    "*://www.edreams.hk/*",
    "*://www.edreams.in/*",
    "*://www.edreams.jp/*",
    "*://www.edreams.ph/*",
    "*://www.edreams.ma/*",
    "*://www.edreams.ae/*",
    "*://www.edreams.net/*",
    "*://www.supersaver.ru/*",
    "*://www.onetwotrip.com/*",
    "*://*.aeroflot.ru/*",
    "*://www.finnair.com/*",
    "*://*.lufthansa.com/*",
    "*://*.austrian.com/*",
    "*://www.turkishairlines.com/*",
    "*://www.swiss.com/*",
    "*://www.britishairways.com/*",
    "*://*.klm.com/*",
    "*://*.klm.ru/*",
    "*://www.virginatlantic.com/*",
    "*://*.airfrance.ru/*",
    "*://*.airfrance.us/*",
    "*://*.airfrance.com/*",
    "*://*.airfrance.co.uk/*",
    "*://*.airfrance.de/*",
    "*://*.airfrance.es/*",
    "*://*.airfrance.it/*",
    "*://*.airfrance.ua/*",
    "*://*.airfrance.pl/*",
    "*://*.s7.ru/*",
    "*://www.travelocity.com/*",
    "*://*.hotwire.com/*",
    "*://www.priceline.com/*",
    "*://www.cheapoair.com/*",
    "*://api4.aviakassa.ru/*",
    "*://api.go2see.ru/api/*",
    "*://www.onetwotrip.com/_api/*",
    "https://safefly.me/*",
    "history",
    "tabs",
    "storage",
    "notifications"
  ],
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "safeflyme@gmail.com",
      "strict_min_version": "53.0"
    }
  }
}