Examine source code of Break Logger

{
  "manifest_version": 2,
  "id": "85dd2aca-7d9f-4217-b008-4c2466e1218c",
  "name": "Break Logger",
  "version": "1.1",
  "description": "Track Coffee and Lunch Breaks automatically.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "host_permissions": [
    "*://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*/desktop/*"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{83477215-4aeb-4f12-b4a8-852f28f8658a}"
    }
  }
}