Examine source code of Web Telegram Online

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "version": "1.0",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "icon16.png",
      "32": "icon32.png",
      "48": "icon48.png",
      "96": "icon96.png",
      "128": "icon128.png",
      "256": "icon256.png"
    },
    "default_popup": "popup.html",
    "default_title": "Web Telegram Online extension"
  },
  "homepage_url": "https://web.tel.onl",
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "96": "icon96.png",
    "128": "icon128.png",
    "256": "icon256.png"
  }
}