Examine source code of Horseshoe

{
  "manifest_version": 2,
  "name": "Horseshoe",
  "version": "1.1resigned1",
  "description": "Finds magnet links in pages.",
  "icons": {
    "48": "icons/magnet-48.png",
    "96": "icons/magnet-96.png"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "horseshoe_background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "horseshoe.js"
      ]
    }
  ],
  "page_action": {
    "browser_style": true,
    "default_icon": {
      "48": "icons/magnet-48.png",
      "96": "icons/magnet-96.png"
    },
    "default_title": "Magnet links",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4c2d7fd7-0d3b-4d6b-ba55-08589c949432}"
    }
  }
}