Examine source code of TempTab

{
  "manifest_version": 2,
  "name": "TempTab",
  "version": "1.2",
  "description": "Opens links in temporary tabs that close automatically after user-defined time.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "TempTab",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6762bb9f-d316-42ae-85e6-f4539fac66ad}",
      "strict_min_version": "89.0"
    }
  },
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  }
}