Examine source code of Badge Count Up Timer

{
  "manifest_version": 2,
  "name": "Badge Count Up Timer",
  "version": "1.0.9",
  "description": "Shows a Count Up Timer in extension Badge.",
  "icons": {
    "512": "icon512x512.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "512": "icon512x512.png"
    },
    "default_title": "refresh",
    "default_popup": "popup.html"
  },
  "background": {
    "page": "background.html",
    "persistent": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f7dc36e1-0e3c-4c1c-930f-ead57286b904}"
    }
  }
}