Examine source code of Session Auto Expiry

{
  "manifest_version": 2,
  "name": "Session Auto Expiry",
  "version": "1.0",
  "description": "Automatically closes private tabs after a set time.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{abbc5e4a-b8d2-4226-a7de-19abb80c0c2a}"
    }
  }
}