Examine source code of Jisho Lookup

{
  "manifest_version": 2,
  "name": "Jisho Lookup",
  "version": "1.0.2",
  "description": "Right-click a word and search it on Jisho.org",
  "permissions": [
    "contextMenus",
    "tabs"
  ],
  "background": {
    "scripts": [
      "jisho-lookup.js"
    ]
  },
  "icons": {
    "16": "icons/jisho-logo.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/jisho-logo.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{463d791d-d8f3-4bea-adfb-0fa34bc83179}"
    }
  }
}