Examine source code of FlashTab

{
  "manifest_version": 2,
  "name": "FlashTab",
  "description": "5 JavaScript interview flash cards every time you open a new tab. Practice locally — no account needed.",
  "version": "0.1.0",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "flashtab@ainga.me",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  }
}