Examine source code of Rename Tabs

{
  "manifest_version": 2,
  "name": "Tab Renamer",
  "version": "1.0",
  "description": "Rename your Firefox tabs with a right-click",
  "permissions": [
    "tabs",
    "contextMenus",
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Tab Renamer"
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d7a3cf5b-0aaa-4769-b119-5d6001aaaeb8}"
    }
  }
}