Ask HN: Capstone Course Project Ideas?

Hello HN :)

I am an enrolled in a capstone course this academic term and my group and I are brainstorming ideas for some program/software to make. I thought to ask the community for some ideas. The only requirement the professor asks for is that the project is legal :)

We are open to ideas from any field/domain/application. Ideas can be a part of a bigger project like developing a startup or smaller like a calculator or anything in between.