Examine source code of GridsUP

{
  "name": "GridsUP",
  "description": "Speed Dial & Productivity",
  "version": "1.0.3",
  "manifest_version": 2,
  "permissions": [
    "management",
    "storage",
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Add Site to your Gridsup!",
    "default_popup": "popup.html",
    "default_icon": {
      "128": "logo.png"
    }
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "icons": {
    "128": "logo.png"
  }
}