Examine source code of Telegram Launch

{
  "applications": {
    "gecko": {
      "id": "TelegramLaunch@9holotpk",
      "strict_min_version": "51.0"
    }
  },
  "browser_action": {
    "default_icon": "icons/telegram_128.png",
    "default_title": "Telegram Launch"
  },
  "description": "Fast Launcher for Telegram Web",
  "icons": {
    "32": "icons/telegram_32.png",
    "64": "icons/telegram_64.png",
    "128": "icons/telegram_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://web.telegram.org/*"
      ],
      "run_at": "document_end",
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "name": "Telegram Launch",
  "version": "2.1resigned1",
  "manifest_version": 2,
  "permissions": [
    "tabs",
    "https://web.telegram.org/",
    "activeTab"
  ],
  "developer": {
    "url": "http://twitter.com/9holotpk",
    "name": "Sontaya T. Wichakot"
  }
}