Examine source code of Quick Notes i

{
  "manifest_version": 2,
  "name": "Quick Notes",
  "version": "1.0",
  "description": "Take quick notes directly in your browser.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f62d3dca-be44-4c70-a3c4-c436413fadd5}"
    }
  }
}