Examine source code of Length Converter Basic

{
  "manifest_version": 2,
  "name": "Length Converter Basic",
  "version": "1.0",
  "description": "The Length Converter is an intuitive web-based application that eliminates the complexities associated with manual conversions",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/leg-logo.png"
    }
  },
  "icons": {
    "128": "images/leg-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fb374cce-7a31-48b3-a55b-35c0fd60bf03}"
    }
  }
}