Examine source code of CryptoTicker

{
  "name": "CryptoTicker",
  "version": "3.0.0",
  "description": "Top 10 Cryptocurrency Price Ticker",
  "manifest_version": 2,
  "icons": {
    "16": "files/img/icon.png",
    "48": "files/img/icon.png",
    "128": "files/img/icon.png"
  },
  "browser_action": {
    "default_icon": "files/img/icon.png",
    "default_popup": "ticker.html"
  },
  "background": {
    "scripts": [
      "files/js/ticker.js"
    ]
  }
}