Examine source code of KnowBias

{
  "name": "KnowBias",
  "version": "0.2.1resigned1",
  "description": "KnowBias is a tool that predicts the degree of political bias of web content on a left-right axis.",
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "http://knowbias.ml/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icon_16.png",
      "48": "assets/icon_48.png",
      "128": "assets/icon_128.png"
    }
  },
  "icons": {
    "16": "assets/icon_16.png",
    "48": "assets/icon_48.png",
    "128": "assets/icon_128.png"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd172865-2370-4355-87ec-83a91e08d8e2}"
    }
  }
}