Examine source code of Wiktionary Lookup

{
  "manifest_version": 2,
  "name": "Wiktionary Lookup",
  "version": "0.7.2resigned1",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup/index.html",
    "default_title": "Lookup a definition!"
  },
  "icons": {
    "186": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{469346ca-d827-4df1-afee-f1d16ead4fb5}"
    }
  }
}