Examine source code of Pomodoro Timer

{
  "manifest_version": 3,
  "name": "Pomodoro Timer",
  "description": "A customizable Pomodoro timer with sound selection.",
  "version": "3.0",
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icon48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "abhirajverma358@gmail.com"
    }
  }
}