Examine source code of ToDo Manager

{
  "manifest_version": 2,
  "name": "ToDo Manager",
  "version": "1.0",
  "description": "Manage your tasks directly from your browser.",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{51189f60-ebd6-44f7-8894-70cb694e6255}"
    }
  }
}