Examine source code of PlugIn-Checker

{
  "description": "Überprüfe deine PlugIns schnell und einfach auf Aktualisierungen",
  "manifest_version": 2,
  "name": "PlugIn-Checker",
  "version": "10.2resigned1",
  "homepage_url": "https://loox.tools/firefox/plugin-checker/",
  "icons": {
    "48": "data/icon48.png"
  },
  "applications": {
    "gecko": {
      "id": "jid0-c1av474BVPIHcGJfBp3GkhlhAa4@jetpack"
    }
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "data/icon48.png",
    "default_title": "PlugIn-Check",
    "default_popup": "https://www.mozilla.org/plugincheck/?plugin-checker"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.mozilla.org/*/plugincheck/?plugin-checker"
      ],
      "js": [
        "data/check.js"
      ],
      "css": [
        "data/check.css"
      ]
    }
  ]
}