Ask HN: What telegram bot should I build?

I'm a competent game developer without any server-side experience. I recently noticed the rise of chat apps and bots in them, and Telegram, with their open bot API, seems like a good place to start building something. But after writing a couple of simple exercises, I find myself unsure what to build next. (I constantly see new bots released for Slack, but this office-oriented network is a completely different story).

What seems like a good bot that would be not prohibitively hard to implement (so, without features like natural language processing) and at the same time, useful to people?