Examine source code of Show fixed Go

{
  "applications": {
    "gecko": {
      "id": "showgo-updated@supernova00"
    }
  },
  "manifest_version": 2,
  "name": "Show fixed Go",
  "version": "4.1resigned1",
  "description": "Always show the go button in the location bar...not just when you type in the location bar.",
  "homepage_url": "https://addons.mozilla.org/en-US/firefox/addon/show-fixed-go/",
  "icons": {
    "38": "icons/icon38.png"
  },
  "author": "krzysztof113",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "page_action": {
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png"
    },
    "default_title": "Go"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}