Examine source code of Billify

{
  "manifest_version": 2,
  "name": "Billify",
  "version": "1.1resigned1",
  "description": "Replaces all images with something better.",
  "icons": {
    "48": "icons/bill-48.jpg"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/bill-32.jpg",
    "default_title": "Billify",
    "default_popup": "pages/pop.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7e0d6678-0e41-4271-a96a-6757eb05d13c}"
    }
  }
}