I'd like to make something like Goalist, but that uses org-mode as a backend.
I find the Goalist interface excellent for a really fine-grained day plan. But it's not libre software, and the file format is not easily shareable.
It would be a fun project to recreate some of its functionality using org-mode as the underlying system.
It'd probably make sense to build it as a native Android ap, but If I did it myself, I'd probably use vue.js as a means to learning that.
Separate file of active timestamps. Increase decrease time. Move up and down. Set which files to include.
It's kind of a fancy agenda view, I guess.