Examine source code of Data Padlock

{
  "manifest_version": 2,
  "name": "Data Padlock",
  "version": "3.0.0",
  "description": "Secure your files & messages using encryption!",
  "author": "Wesley Branton",
  "developer": {
    "name": "Wesley Branton",
    "url": "http://addons.wesleybranton.com"
  },
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_icon": "icons/icon-96.png",
    "default_title": "Data Padlock"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "downloads",
    "storage"
  ]
}