Examine source code of Gene Info eXtension (GIX)

{
  "manifest_version": 2,
  "name": "Gene Info",
  "version": "1.8.3",
  "description": "View gene information by double clicking a gene name or accession on any webpage.",
  "icons": {
    "16": "icon/icon16.png",
    "48": "icon/icon48.png",
    "128": "icon/icon128.png"
  },
  "author": "James Knight",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icon/icon16.png",
      "24": "icon/icon24.png",
      "32": "icon/icon32.png"
    },
    "default_title": "Gene Info",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ]
}