This would most certainty be part of the used subscriber. I’m not sure if any of the existing subscribers support it, but in the worst case you can write your own subscriber that wraps an existing one.

It depends on how you want to store your data. Every OS has a standard for where applications should store their data. You should store your data at the appropriate path. If you have structured data against which you want to run queries you could use a sqlite DB (the sqlx crate supports sqlite) instead of just a bunch of config files.

I have built my own launcher that consists of two rows of apps on the bottom of the screen which are auto populated with my most used apps. Additional there is a “swipe down to search” view for all other apps. Nothing else.

What can it do that macos built-in screenshots and preview can’t do?

I’m curious. What workflow do you have that requires window snapping? I’m asking because I have no use for window snapping and I’m trying to understand why people require it.