Examine source code of Expirable Tabs

{
  "applications": {
    "gecko": {
      "strict_min_version": "58.0a1",
      "id": "{625c9fc9-ae53-4d23-ab9d-7f38fa57e390}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "Expirable Tabs",
    "default_popup": "tabs.html",
    "default_icon": {
      "16": "images/icon-left-16.png",
      "32": "images/icon-left-32.png"
    }
  },
  "description": "Set an expiration date for tabs in order to close them automatically after a period of time.",
  "homepage_url": "https://github.com/ohanetz/expirable-tabs",
  "manifest_version": 2,
  "name": "Expirable Tabs",
  "permissions": [
    "tabs",
    "storage",
    "alarms"
  ],
  "icons": {
    "48": "images/icon-48.png",
    "96": "images/icon-96.png"
  },
  "version": "1.1.2resigned1"
}