Examine source code of Discount Tracker

{
  "name": "__MSG_appName__",
  "version": "2.9.18",
  "manifest_version": 2,
  "description": "__MSG_appDescription__",
  "icons": {
    "16": "icons/sepet-16.png",
    "32": "icons/sepet-32.png",
    "48": "icons/sepet-48.png",
    "128": "icons/sepet-128.png"
  },
  "default_locale": "en",
  "background": {
    "persistent": true,
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage",
    "https://api.discountr.info/*",
    "https://www.trendyol.com/*",
    "https://m.trendyol.com/*",
    "https://trendyol.com/*",
    "https://www.vatanbilgisayar.com/*",
    "https://m.modanisa.com/*",
    "https://www.modanisa.com/*",
    "https://www.boyner.com.tr/*",
    "https://www.n11.com/*",
    "https://m.n11.com/*",
    "https://urun.n11.com/*"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.trendyol.com/*",
        "https://m.trendyol.com/*",
        "https://trendyol.com/*",
        "https://www.vatanbilgisayar.com/*",
        "https://m.modanisa.com/*",
        "https://www.modanisa.com/*",
        "https://www.boyner.com.tr/*",
        "https://www.n11.com/*",
        "https://m.n11.com/*",
        "https://urun.n11.com/*",
        "https://www.migros.com.tr/*",
        "https://www.defacto.com.tr/*",
        "https://m.defacto.com.tr/*",
        "https://www.a101.com.tr/*",
        "https://www.kitapyurdu.com/*",
        "https://m.kitapyurdu.com/*",
        "https://www.watsons.com.tr/*",
        "https://www.teknosa.com/*",
        "https://www.carrefoursa.com/*",
        "https://www.koton.com/*",
        "https://m.koton.com/*",
        "https://www.morhipo.com/*",
        "https://www.epttavm.com/*"
      ],
      "js": [
        "scripts/contentscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/sepet-16.png",
      "32": "icons/sepet-32.png",
      "48": "icons/sepet-48.png",
      "128": "icons/sepet-128.png"
    },
    "default_title": "Discount Tracker",
    "default_popup": "popup.html"
  },
  "applications": {}
}