Examine source code of Route Tracker

{
  "manifest_version": 2,
  "name": "Route Tracker",
  "version": "1.0",
  "description": "Allows users to input routes and track traffic manually.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "storage",
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4f85afdd-a4d7-41d3-aafe-4092ba65c03c}"
    }
  }
}