Examine source code of S_Calculator

{
  "name": "S_Calculator",
  "description": "Simple Calculator",
  "version": "0.0.2",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": "logo.png"
  },
  "icons": {
    "64": "logo.png",
    "128": "logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{af3dc72b-9213-4277-9b76-9d7e37ac1b05}"
    }
  }
}