Examine source code of Simple Notes

{
  "manifest_version" : 2 ,
  "name" : "Mini Notes",
  "version" : "1.0",
  "description" : "Quick note-taking extension right in your browser.",
  "browser_action" : {
    "default_popup" : "popup.html",
    "default_icon" : {
      "16" : "icon.png",
      "32" : "icon.png"
    }
  },
  "permissions" : [
    "storage" 
  ],
  "icons" : {
    "16" : "icon.png",
    "32" : "icon.png",
    "48" : "icon.png",
    "128" : "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{88091e40-be8b-4f8d-ac2b-03b1ec70eb1d}"
    }
  }
}