Examine source code of Splash

{
  "manifest_version": 3,
  "name": "Splash",
  "description": "Get a splash of color on your browser new tab page with this speedy customizable extension",
  "version": "3.0.3",
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "action": {
    "default_title": "New Tab"
  },
  "permissions": [
    "topSites"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "splash-new-tab@fxzfun.com"
    }
  },
  "homepage_url": "https://fxzfun.com/splash",
  "icons": {
    "16": "imgs/splash (16x16).png",
    "64": "imgs/splash (64x64).png",
    "128": "imgs/splash (128x128).png",
    "512": "imgs/splash (512x512).png"
  }
}