Examine source code of vSecure

{
  "manifest_version": 2,
  "name": "vSecure",
  "description": "This extension is for securing text strings in an easy way. It can encrypt strings, so they will be secure to be stored.",
  "version": "2.0.4resigned1",
  "applications": {
    "gecko": {
      "id": "iacido@gmail.com"
    }
  },
  "permissions": [],
  "browser_action": {
    "default_icon": {
      "19": "images/icon19.png",
      "38": "images/icon38.png"
    },
    "default_title": "vSecure - Securing text string easier.",
    "default_popup": "index.html#form"
  }
}