Examine source code of Grammar Checker V2

{
  "manifest_version": 2,
  "name": "Grammar Checker V2",
  "version": "1.3",
  "description": "Scan and check grammar and spelling on any webpage using LanguageTool.",
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "*://*/*"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/logo_32.png",
      "64": "icons/logo_64.png",
      "128": "icons/logo_128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d43b59c5-3374-42c8-a6c1-abfcc293c87d}"
    }
  }
}