Examine source code of Simple New Tab

{
  "manifest_version": 2,
  "name": "Simple New Tab",
  "version": "1.0",
  "description": "A Minimalistic and Elegant New Tab Page.",
  "icons": {
    "48": "assets/icon48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@thatcrispytoast.github.io"
    }
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  }
}