The end-of-day shutdown is just that. You put your work day in order, you make sure your papers are tidy, you check what you need to do tomorrow (no nasty surprises) and perhaps a few days ahead, then you actually say, out loud, “shutdown complete”.
It’s supposed to help separate your day of (deep) work from your time off. I like the idea but – ha! – never remember to do it.
OP: cool looking app, it’s really nicely done. Was this a “teach myself a language” sort of project? If not, what was the motivation? [Edit: just seen your comment below.]