Examine source code of TypeLingo

{
  "manifest_version": 2,
  "name": "TypeLingo",
  "version": "1.1.9",
  "developer": {
    "name": "Nowam"
  },
  "description": "Duolingo typing restored! Get back the ability to type your responses.",
  "icons": {
    "128": "icons/128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "*://*.duolingo.com/*",
    "*://d35aaqx5ub95lt.cloudfront.net/js/*.js",
    "webRequest",
    "webRequestBlocking"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{308c7f88-d5d2-4597-8b2e-3d7aef9c70bb}"
    }
  }
}