Examine source code of ez epoch

{
  "manifest_version": 2,
  "name": "ez epoch",
  "version": "0.1",
  "description": "Extension to detect and convert epoch timestamps",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon2.png",
    "32": "icons/icon2.png",
    "48": "icons/icon2.png",
    "64": "icons/icon2.png",
    "128": "icons/icon2.png",
    "256": "icons/icon2.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "popup.html",
    "popup.js"
  ],
  "applications": {
    "gecko": {
      "id": "5d068096-b755-437e-9aa0-a7df05d28436@mokachika.com"
    }
  }
}