Timer

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Timer",
  "version": "1.3.0.2",
  "manifest_version": 2,
  "description": "This simple timer tells you when your time is up.",
  "icons": {
    "16": "img/16.png",
    "32": "img/32.png",
    "48": "img/48.png",
    "128": "img/128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "img/clock.png",
    "default_popup": "popup.html"
  },
  "minimum_chrome_version": "50",
  "offline_enabled": true,
  "permissions": [
    "notifications",
    "storage"
  ],
  "web_accessible_resources": [
    "img/48.png"
  ]
}