Examine source code of nextab

{
  "name": "nextab",
  "version": "1.4.14resigned1",
  "manifest_version": 2,
  "description": "Extension provides lightweight New Tab for your browser with backgrounds from unsplash.com",
  "chrome_url_overrides": {
    "newtab": "new_tab.html"
  },
  "icons": {
    "16": "images/logo_16.png",
    "32": "images/logo_32.png",
    "48": "images/logo_48.png",
    "96": "images/logo_96.png",
    "128": "images/logo_128.png",
    "256": "images/logo_256.png",
    "512": "images/logo_512.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bcd40e51-6cfa-4d3c-abfb-94a33834af83}"
    }
  }
}