Examine source code of Management Tools

{
  "manifest_version": 2,
  "name": "Management Tools",
  "author": "T_Rex",
  "version": "0",
  "applications": {
    "gecko": {
      "id": "sixpalax@yandex.com",
      "strict_min_version": "52.0"
    }
  },
  "description": "Modify User-Agent ",
  "icons": {
    "48": "icons/if_source_code_103710.svg"
  },
  "permissions": [
    "<all_urls>",
    "webRequest",
    "webRequestBlocking",
    "tabs"
  ],
  "browser_action": {
    "default_icon": {
      "32": "icons/if_source_code_103710.svg"
    },
    "default_title": "User script",
    "default_popup": "popup/user-script.html",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}