Examine source code of Base64 Tools

{
  "manifest_version": 2,
  "name": "Base64 Tools",
  "version": "0.1",
  "description": "A collection of Base64 tools, including encode & decode",
  "icons": {
    "48": "icons/base64-tools-48.png"
  },
  "browser_action": {
    "default_popup": "popup/page.html",
    "default_icon": {
      "16": "icons/page-16.png",
      "32": "icons/page-32.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{579e1071-43ad-4d25-b5d3-bd7299e093be}"
    }
  }
}