Examine source code of Tab-Auto-Refresher

{
  "manifest_version": 2,
  "name": "Tab-Auto-Refresher",
  "version": "0.1.2",
  "description": "Allows to automatically refresh multiple Tabs independently",
  "icons": {
    "64": "icons/wc_64x64.png",
    "128": "icons/wc_128x128.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background_script.js"
    ]
  },
  "browser_action": {
    "default_area": "navbar",
    "default_icon": {
      "64": "icons/wc_64x64.png",
      "128": "icons/wc_128x128.png"
    },
    "default_popup": "popup/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9017f697-33ca-4097-937f-6a2577e20380}"
    }
  }
}