Examine source code of The Timer

{
  "manifest_version": 2,
  "name": "Task Timer",
  "version": "1.0",
  "description": "Create timer",
  "author": "Bozidar Atanasovski",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "/popup.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "/icons/icon.png"
    },
    "default_title": "Task Timer"
  },
  "background": {
    "scripts": [
      "/background.js"
    ]
  },
  "permissions": [
    "alarms",
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6dabfbb9-d8ff-40b9-97c7-15c38d98d20c}"
    }
  }
}