Examine source code of insta-viewer

{
  "manifest_version": 2,
  "name": "insta-viewer",
  "version": "1.0",
  "description": "View Instagram Accounts Without Having An Account",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "https://www.instagram.com/"
  ],
  "background": {
    "scripts": [
      "insta-viewer.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6e93c3e7-69c3-4ac6-a88d-873148baccdd}"
    }
  }
}