Examine source code of JBModify

{
  "manifest_version": 2,
  "name": "JBModify",
  "version": "0.2",
  "description": "jbmod!!",
  "applications": {
    "gecko": {
      "id": "{2f27415c-917c-40b1-b0be-8ac721a7c5a5}",
      "strict_min_version": "96.0"
    }
  },
  "browser_action": {
    "default_icon": "assets/icons/endorsed.png",
    "default_popup": "popup.html",
    "default_title": "JBModify"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "250": "assets/icons/endorsed.png"
  },
  "web_accessible_resources": [
    "assets/images/*.png",
    "sound_page.html",
    "sound_page.js",
    "404.mp3"
  ]
}