Examine source code of Free Agency Matrix

{
  "manifest_version": 2,
  "name": "Free Agency Matrix",
  "version": "1.2.1",
  "description": "An extension for Pennant Wars that calculates minimum offers for Free Agents.",
  "icons": {
    "48": "/images/pw_48.jpg"
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": "images/pw_48.jpg",
    "default_title": "FA Matrix",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{989892bd-4e45-4a3a-bad3-562dd4c35f6b}"
    }
  }
}