Hello everyone,

I'm the developer of Breathink Basic, an outliner for Mac.

I used to love Tree's horizontal outlining view. I missed that experience, so I built Breathink Basic for my own writing and planning.

Breathink Basic lets you switch between a vertical outline and a horizontal tree view. You can rearrange items, change their hierarchy, collapse sections, and focus on one part of an outline.

A few practical details:

- Requires macOS 12 or later and an Apple Silicon Mac.
- US$9.99 on the US Mac App Store, as a one-time purchase with no subscription.
- Documents stay on your Mac. No account is required, and the app has no AI features.
- Exports to OPML, Markdown, HTML, plain text, and PDF.
- The interface supports English and Japanese.

Breathink Basic on the Mac App Store:
https://apps.apple.com/us/app/breathink-basic/id6787563209

I'd be interested to hear how you use horizontal outlines in your writing or planning, and which outlining features you find most useful.

Disclosure: I used AI to help draft the English wording of this post.

Nice to see a return to Tree, which was a great app.

We've also discussed Traverse (for Mac) in this forum: also does horizontal outlining, in a slightly different way.