I also built my own note-taking app[1] out of frustration of existing apps, so I can relate to the author.

I wanted:

- A flexible block editor like Notion.

- That runs natively and FAST (unlike Notion).

- Where the underlying data is always plain text (Markdown formatted).

I wrote about its development on my blog[2].

[1] http://get-notes.com

[2] https://rubymamistvalove.com/block-editor