Examine source code of Form Hack

{
  "name": "Hack the Form",
  "description": "A usefull add-on for web developers to view hidden inputs in form.",
  "version": "0.5resigned1",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "background": {
    "scripts": [
      "main.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icons/icon-96.png",
    "default_title": "Hack the Form"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{f6493a83-5202-4427-a971-24b6da0fe2e5}"
    }
  }
}