Examine source code of CountDemTabs

{
  "name": "CountDemTabs",
  "short_name": "CountDemTabs",
  "author": "stapmoshun",
  "developer": {
    "name": "stapmoshun"
  },
  "version": "1.2.0",
  "description": "A great badge for showing tab count, including an animation for 1000+ tabs!",
  "homepage_url": "https://github.com/jpfleischer/tab-counter",
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "d89082b0-1c90-4d48-95b7-6bc6861e1bc2@stapmoshun",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "1": "icons/tabcounter-logo.plain.min.svg"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_action": {
    "browser_style": true,
    "default_area": "tabstrip",
    "default_icon": "icons/tabcounter.plain.min.svg",
    "theme_icons": [
      {
        "dark": "icons/tabcounter-gray10.plain.min.svg",
        "light": "icons/tabcounter-gray90.plain.min.svg",
        "size": 1
      }
    ],
    "default_popup": "src/popup.html",
    "default_title": "Tab Counter"
  },
  "options_ui": {
    "page": "src/options.html"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ],
    "persistent": true
  }
}