Examine source code of Statistics Calculator

{
  "manifest_version": 2,
  "name": "Statistics Calculator",
  "version": "1.0",
  "description": "Calculate mean, median, mode, variance, and standard deviation for a dataset.",
  "icons": {
    "48": "icons/stats-calculator-icon-48.png"
  },
  "permissions": [],
  "browser_action": {
    "default_icon": "icons/stats-calculator-icon-48.png",
    "default_popup": "popup.html",
    "default_title": "Stats Calculator"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{48d10004-24b7-4dc4-adfb-fa199df14d25}"
    }
  }
}