Examine source code of knutStream

{
  "manifest_version": 2,
  "name": "knutStream",
  "version": "1.4",
  "description": "Get a notification whenever knut goes live",
  "browser_action": {
    "default_popup": "popup/index.html",
    "default_icon": "icons/128-light.png",
    "theme_icons": [
      {
        "light": "icons/16-light.png",
        "dark": "icons/16-dark.png",
        "size": 16
      },
      {
        "light": "icons/48-light.png",
        "dark": "icons/48-dark.png",
        "size": 48
      },
      {
        "light": "icons/128-light.png",
        "dark": "icons/128-dark.png",
        "size": 128
      }
    ]
  },
  "background": {
    "page": "background/background.html"
  },
  "icons": {
    "16": "icons/16-light.png",
    "48": "icons/48-light.png",
    "128": "icons/128-light.png"
  },
  "incognito": "spanning",
  "permissions": [
    "notifications",
    "identity",
    "alarms",
    "tabs"
  ]
}