Examine source code of Pomodoro Timer Plus

{
  "manifest_version": 2,
  "name": "Pomodoro Timer Plus",
  "version": "1.0",
  "description": "Pomodoro Timer with additional productivity features",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "storage",
    "notifications",
    "alarms"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Pomodoro Timer Plus",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e850d9b2-b41f-41c5-bbad-d068142b70a4}"
    }
  }
}