Examine source code of Quick Notes Plus

{
  "manifest_version": 2,
  "name": "Quick Notes",
  "version": "1.0",
  "description": "Allows users to quickly save and view notes from any webpage.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a8e3d8c1-c158-4a74-af19-2daa48288171}"
    }
  }
}