Examine source code of Generate QR Code

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "manifest_version": 2,
  "name": "Generate QR Code",
  "description": "Generate QR Code for the active tab",
  "version": "0.0.5resigned1",
  "permissions": [
    "activeTab",
    "contextMenus",
    "tabs"
  ],
  "applications": {
    "gecko": {
      "id": "qrcode@linuxmail.org"
    }
  }
}