Countdown Timer

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Countdown Timer",
  "description": "A Countdown Timer",
  "icons": {
    "16": "clock16.png",
    "48": "clock48.png",
    "128": "clock128.png"
  },
  "version": "1.0.1",
  "permissions": [
    "notifications",
    "storage"
  ],
  "browser_action": {
    "default_popup": "timer.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}