I built a new notes app which lets you organize notes into an outline shape.

The core idea is that after you've written a note, you can add "subnotes" to it. Those subnotes can have subnotes, etc., so it often ends up in a tree shape. However, one twist is that you can place a note into multiple subnote lists. This ends up making them like "transclusions" which you can use as a sort of portal to jump to different outlines that use the note.

Even though it's an outline shape, you're not required to treat the relationships as hierarchical, of course. The main reason I went with this model is I wanted to be able to collect similar ideas together and reorder them as needed. The parent notes become sort of like folders for other notes, but having a model that just uses notes makes it much easier to work with since every note could become a parent (i.e. one big reason we all like outliners).

Notes also don't need to be titled, which I always found annoying in another notes apps. Just create a new note and start typing the text you want in it. Notes get assigned unique identifiers, which you can use for traditional hypertext links within the note itself.

After you use it a while, you end up with lots of "neighborhoods" of trees with different notes in them, which you can jump between using shared notes. This is another nice thing about the model: a notebook can have multiple trees in it and they don't all have to be part of a larger uber-tree.

Learn more: https://understory.ussherpress.com/
And a short video showing how it works: https://www.youtube.com/watch?v=XDzV6OrcP4s