Bootstrap 4 Responsive Helper

manifest.json

{
  "manifest_version": 2,
  "name": "Bootstrap 4 Responsive Helper",
  "version": "1.0",
  "description": "Shows the active Bootstrap 4 grid breakpoint on current page.",
  "icons": {
    "16": "icons/16px.png",
    "32": "icons/32px.png",
    "48": "icons/48px.png",
    "64": "icons/64px.png",
    "128": "icons/128px.png",
    "256": "icons/256px.png",
    "300": "icons/300px.png",
    "512": "icons/512px.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/16px.png",
      "32": "icons/32px.png",
      "48": "icons/48px.png",
      "64": "icons/64px.png",
      "128": "icons/128px.png",
      "256": "icons/256px.png",
      "300": "icons/300px.png",
      "512": "icons/512px.png"
    },
    "default_title": "Bootstrap 4 Responsive Helper"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "update_url": "https://edge.microsoft.com/extensionwebstorebase/v1/crx"
}