Examine source code of CTRL - Tab Switcher

{
  "manifest_version": 2,
  "name": "CTRL - Tab Switcher",
  "version": "1.0",
  "description": "Switch quickly between tabs, by pressing control + the first letter of a domain.",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon-48.jpeg",
    "96": "icon-96.jpeg"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e83924bd-f75b-47f8-9f70-4f9ab0a30ce3}"
    }
  }
}