Examine source code of Re-Focus

{
  "manifest_version": 2,
  "name": "Re-Focus",
  "description": "Stay focused and motivated everytime you open a new tab!",
  "version": "1.1",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Re-Focus"
  },
  "page_action": {
    "default_icon": {
      "16": "images/16x16.png",
      "32": "images/32x32.png",
      "48": "images/48x48.png",
      "128": "images/128x128.png"
    }
  },
  "icons": {
    "16": "images/16x16.png",
    "32": "images/32x32.png",
    "48": "images/48x48.png",
    "128": "images/128x128.png"
  }
}