I built a GPT-4 powered walking tour app during a hackathon. It uses the Wikipedia and Google Maps APIs to find interesting facts about things you're walking by and generates scripts to read aloud. It's fun and I learned a lot about places I go to all the time.

Unfortunately all the APIs are pretty costly so I can't post it for the group. Now that OpenAI's TTS and GPT-4 Turbo is out, I could probably revisit it. Still, not sure if people would be willing to pay enough for something like this.