Examine source code of Bitmoji (NOT OFFICIAL)

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Bitmoji",
  "short_name": "Bitmoji",
  "description": "Use Bitmoji anywhere on web!",
  "version": "10.31.1190",
  "icons": {
    "48": "images/bitmoji-logo-48.png",
    "128": "images/bitmoji-logo-128.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "cookies",
    "clipboardWrite",
    "webRequest",
    "webRequestBlocking",
    "webNavigation",
    "*://mail.google.com/*",
    "*://*.bitbucket.org/*",
    "*://*.github.com/*",
    "*://*.atlassian.net/*",
    "*://*.bitmoji.com/*"
  ],
  "background": {
    "scripts": [
      "dist/chrome-extension-background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "19": "images/bitmoji-icon-19.png",
      "38": "images/bitmoji-icon-38.png"
    },
    "default_popup": "popup.html"
  },
  "externally_connectable": {
    "matches": [
      "https://test.bitmoji.com/account_v2/*",
      "https://www.bitmoji.com/account_v2/*"
    ]
  },
  "web_accessible_resources": [
    "static/media/*.svg",
    "static/media/*.png",
    "popup.html"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "https://bitbucket.org/*",
        "https://*.github.com/*",
        "https://*.atlassian.net/*",
        "*://*.bitmoji.com/*"
      ],
      "js": [
        "thirdparty/jquery.min.js",
        "thirdparty/sweetalert.min.js",
        "thirdparty/webpicker-sdk.js",
        "dist/bitmoji-chrome-extension.js",
        "dist/chrome-extension-page-detector.js"
      ],
      "css": [
        "thirdparty/webpicker-sdk.css",
        "dist/chrome-extension.css"
      ],
      "run_at": "document_end"
    }
  ]
}