Examine source code of FairCoin Calculator

{
  "manifest_version": 2,
  "name": "FairCoin Calculator",
  "version": "1.3resigned1",
  "permissions": [
    "webRequest",
    "<all_urls>",
    "*://api.fairplayground.info/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://chain.fair.to/address*",
        "https://chain.fair-coin.org/address/*"
      ],
      "js": [
        "jquery-3.3.1.min.js",
        "extension.js"
      ]
    }
  ],
  "gecko": {
    "id": "faircoin-calculator@mayel.space"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{28c04ded-5167-4f80-99ed-78bb6ab8c0db}"
    }
  }
}