AI-generated webpage (websim.ai)
Possibilities are entirely up to the whole humanity's imagination combined. websim.ai is an AI website generator that will do anything you want, so long as it's not sexually pornographic. Some guy made a webpage generator generated by websim.ai, and wanted me to use it.
Catto's card picker
My friend created an RPG card game on Obby Creator. He already had a tool that allowed him to pick a new card every 10 seconds, but I suggested a potentially better way: an HTML page that can instantly pick a new card just by reloading the page. It doesn't do much - it just names the card that has been picked.