[hbn]

The other replies aren't very helpful imo

It's essentially an app for taking notes and jotting down ideas, and you write them in markdown. You can link references to other notes within a note to link up ideas.

Here's a 12 minute demo that should give you an idea:

https://www.youtube.com/watch?v=QgbLb6QCK88

I'm not that quite in-depth with my usage of it. I essentially use it as a scratchpad for a few notes for work. But it does the job