kOS by Helper Systems 4+

Unlock the potential of PDFs

Helper Systems LLC

    • 5.0 • 8 Ratings
    • Free
    • Offers In-App Purchases



kOS makes PDFs more useful: research, learn, explore.

Introducing kOS (pronounced ‘chaos’)

kOS helps you discover what is hidden in your PDFs. With kOS, you can:
• Quickly find and navigate to information that is important to you.
• Discover and explore ideas in ways that can save you hours of time.
• Easily extract ideas that can be used as building blocks for further knowledge.
• Instantly track your information back to the original source.

kOS automatically exposes significant words, phrases, and entities by indexing all your PDFs.

kOS enables you to discover more about your PDFS through words and phrases visualized in a word cloud.

kOS helps you dive into your PDFS via a comprehensive list of occurrences for every word or phrase.

kOS saves you time by allowing you to manage and explore multiple sets of PDFs at once.

kOS makes excerpt sharing easy, including citations and one-click sharing to Apple Notes.

You can view the Terms of Service at: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

What’s New

Version 1.1

Import and fully explore hundreds of PDFs in minutes, thanks to our much speedier content processing engine!

Take advantage of powerful new premium features to supercharge your research process:
• Explore content in a brand new way using the Phrase Builder.
• Discover words and phrases common to multiple documents.
• Reduce noise by excluding irrelevant words from the word cloud.
• Highlight text excerpts and annotate them with tags and comments.
• Edit and reorder your notes as you see fit, and share them with others.
• Export your lists of documents and associated metadata to CSV files.

All existing features are still free with some exciting new additions:
• Navigate your documents in either gallery or table view.
• Mark documents, or even pages, as favorites for easy recall.
• Benefit from many bug fixes and improvements.

Ratings and Reviews

5.0 out of 5
8 Ratings

8 Ratings

Jawrugger ,

This is clearly a work of passion

When I first downloaded it, I was struck. No ads, no data collected, and working entirely on my mac. I thought, this is what I've wanted for years and nobody has had the guts to build! The way I've set it up, it's like my own personal intranet, so that I can summarize and discover in any PDF I find. I'll be looking very much forward to subsequent versions, I really want to see where this goes.

3PC0 ,


This app does not collect any data? It essentially allows you to create a library from your PDF files. Organized into user defined subject level databases.

Finally something useful to do with the all of the PDF Files I have been hoarding.

FashionMaven ,

Beautiful, original idea

This is fundamentally a new paradigm for file organization and interaction. Only just beginning to unlock this new motion in my routines but excited to organize my PDFs and make this part of my workflow/funflow/readingflow!

App Privacy

The developer, Helper Systems LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More