Simple Standard Calculator

manifest.json

{
  "manifest_version": 2,
  "name": "Simple Standard Calculator",
  "options_page": "settings.html",
  "description": "A simple standard calculator, works offline too",
  "version": "1.0.0",
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "icons/16.png",
    "24": "icons/24.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "72": "icons/72.png",
    "96": "icons/96.png",
    "128": "icons/128.png"
  },
  "browser_action": {
    "default_title": "Open the calculator",
    "default_popup": "popup.html"
  },
  "offline_enabled": true,
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "update_url": "https://edge.microsoft.com/extensionwebstorebase/v1/crx"
}