Examine source code of Unit Conversion Basic

{
  "manifest_version": 2,
  "name": "Unit Conversion Basic",
  "version": "1.0",
  "description": "Unit Conversion Basic is a utility that allows you to convert units of grams, meters, kilometers... and many other basic features",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/unit-logo.png"
    }
  },
  "icons": {
    "128": "images/unit-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c0fd6946-4154-43f1-97cb-bbb781e9bb3c}"
    }
  }
}