Examine source code of GoogleBlock

{
  "manifest_version": 2,
  "name": "GoogleBlock",
  "version": "1.4",
  "description": "Blocks Google Domains",
  "icons": {
    "48": "icons/logo.png"
  },
  "browser_action": {
    "default_icon": "icons/logo.png",
    "default_title": "GoogleBlock",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background/main.js",
      "background/domainHandler.js",
      "background/request_check.js"
    ]
  },
  "permissions": [
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "tabs"
  ],
  "applications": {
    "gecko": {
      "id": "addon@googleblock.com",
      "strict_min_version": "57.0"
    }
  }
}