Examine source code of To do Time Tracker

{
  "manifest_version": 2,
  "name": "To do Time Tracker",
  "version": "1.0",
  "description": "Summarize and analyze time spent on each task in the to-do list.",
  "permissions": [
    "storage",
    "alarms"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Time Tracker"
  },
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b2b7f8e2-7caa-46c0-9a1f-d90407ba9f2f}"
    }
  }
}