Examine source code of Alt Text Auditor

{
  "manifest_version": 2,
  "name": "Alt Text Auditor",
  "version": "1.0",
  "description": "Audit images on the page for missing alt text.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f02df790-93a5-440d-a9ed-06df4b8b96f4}"
    }
  }
}