Kosshi Outliner

Kosshi Outliner

Markdown, images, device sync

4 ratings
6 reviews
Free
In-App Purchases

Details

  • Released
  • Updated
  • April 2, 2026
  • October 4, 2026

Features

Kosshi Outliner screenshot #1 for iPhone
Kosshi Outliner screenshot #2 for iPhone
Kosshi Outliner screenshot #3 for iPhone
Kosshi Outliner screenshot #4 for iPhone
Kosshi Outliner screenshot #5 for iPhone
Kosshi Outliner screenshot #6 for iPhone
iphone
ipad
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About

This native outliner app allows you to organize thoughts with a hierarchical structure, zoom into specific sections, and format text using Markdown. It supports images, sketches, internal links, and reminders, with seamless iCloud sync across Apple devices.

✓Hierarchical outlining with indentation
✓Zoom into specific rows
✓Markdown formatting
✓Image and file embedding
✓Apple Pencil sketches
✓Internal linking
✓Reminders and calendar sync
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What's New in Kosshi Outliner

1.21.0

October 4, 2026

What's New in 1.21.0 - Save your panes, zoom, search, and sidebar layout as a Workspace, then switch between Workspaces - Recently Deleted keeps removed rows for 30 days and lets you restore them - Find Action makes actions and settings easier to discover - Search text inside attached images - Use Quick Capture through Shortcuts and URLs Note Workspaces are stored on this device only. They are not synced through iCloud and are not included in backups. On an external keyboard, Ctrl+Tab now switches Workspaces. Use Ctrl+Cmd+[ and Ctrl+Cmd+] to move between panes. Important If you use Kosshi on multiple devices, update all of them to 1.21 or later. Older versions may show deleted rows as regular rows; edits made there may be lost when those rows are permanently removed after 30 days.

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Subscriptions & In-App Purchases

$24.99

Kosshi Outliner

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User reviews

Best Outliner I’ve Used

This is a brilliant outliner app. I use outlining a lot for various purposes and I’ve found Kosshi to be the smoothest experience. The integration between Mac and iOS versions is fantastic. I mainly write outlines on my Mac, but view/use many outlines on my iPhone. Being able to easily navigate on the phone, and add content as needed, is done in a thoughtful and intuitive way. Plus the app developer keeps adding important new features. Put simply: best outliner I’ve ever used.
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Response from developer

Thank you for using Kosshi! I’m glad you’re finding it useful. I’ll keep working to make it easy to use across your Apple devices.

Great start

This is an excellent app so far. I’m excited to see where it goes over the next few months. It’s already entirely useable and really fills a space in the iOS and Mac OS cross compatible offline outline apps that no other app fills currently.

Response from developer

Thank you for using Kosshi and for your kind words. I’m glad to hear that it’s useful to you. I’ll continue improving Kosshi and adding new features.

Top Notch Outliner

I love outliners. I love native Mac apps, and I love keeping my data on my computer, not in the cloud. This checks all the boxes, and is remarkably stable for a new app. I love the single file data base approach. This is as close as Mac has come to GrandView - still the best of them all. 

The iPad version has a little catching up to do with the Mac version, especially in find and filter, (the found items are highlighted, but sometimes are not seen in the window as you step through them, filter doesn’t always work) but I am sure that will be fixed soon. Kosshi has already surpassed the competition.

The Desktop version is 5 stars and the iPad version is 3 stars, so I am giving it 4.

Edit: I think the iPad problems were user error. I am changing this review to 5 stars. For my personal use, notes like OmniOutliner would make it perfect, but that is the only change (I won’t call it an improvement) I would like to see.
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Response from developer

Thank you for the thoughtful review! I’m glad you’re enjoying Kosshi. Your kind words mean a lot to me, especially given your many years of experience with outliners.

Top Notch Outliner

I love outliners. I love native Mac apps, and I love keeping my data on my computer, not in the cloud. This checks all the boxes, and is remarkably stable for a new app. I love the single file data base approach. This is as close as Mac has come to GrandView - still the best of them all. 

The iPad version has a little catching up to do with the Mac version, especially in find and filter, (the found items are highlighted, but sometimes are not seen in the window as you step through them, filter doesn’t always work) but I am sure that will be fixed soon. Kosshi has already surpassed the competition.

The Desktop version is 5 stars and the iPad version is 3 stars, so I am giving it 4
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Great potential

This app has a lot of potential. I love the design; it is kind of like an offline Workflowy, which is not a bad thing.

The developer is accessible and responsive, and I have seen the app improve tremendously since I first got it. I am looking forward to watching it grow.

Response from developer

Thank you for using Kosshi and for your kind words! I’m still working on many more updates, and I hope you’ll enjoy watching it grow.

Developer apps

FAQ

What is Kosshi Outliner?

Kosshi Outliner is a fast, native outliner application designed for Mac, iPhone, and iPad. It helps users organize thoughts and ideas with a hierarchical structure, Markdown support, and seamless iCloud synchronization.

Is Kosshi Outliner free?

Yes, Kosshi Outliner is free to download and use. A one-time purchase is available for advanced features and to support development, covering all three Apple platforms.

Does Kosshi Outliner have ads?

No, Kosshi Outliner is ad-free. The app focuses on providing a clean and uninterrupted user experience for organizing thoughts.

What devices is Kosshi Outliner available on?

Kosshi Outliner is available on Mac, iPhone, and iPad. A single purchase unlocks the app across all these Apple devices.

How does Kosshi Outliner sync data?

Kosshi Outliner uses iCloud via CloudKit for syncing. Your outlines are stored in your iCloud account, ensuring data is accessible across your Apple devices and the developer cannot access its contents.

Can I export my outlines from Kosshi Outliner?

Yes, you can export your outlines from Kosshi Outliner in multiple formats, including Markdown, OPML, and plain text. This ensures your data is not locked into the application.

Does Kosshi Outliner support collaboration?

While Kosshi Outliner focuses on individual organization and syncs via iCloud, it does not currently offer real-time collaboration features. Its primary strength lies in personal productivity and thought organization.

How often is Kosshi Outliner updated?

Kosshi Outliner was last updated on June 15, 2026, with version 1.12.0. The developer actively welcomes feature requests and bug reports, suggesting a commitment to ongoing development and improvements.