Comparison

Cardflow+ by Qrayon vs KnowledgeBase Builder

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Cardflow+ by Qrayon

This app digitizes the tactile experience of using index cards on an iPad. It allows users to brainstorm, plan projects, and organize ideas with a flexible, freeform layout. Capture thoughts with writing, drawing, or photos, and arrange them on a digital board.

Highlights
  • Digital index card creation
  • Freeform layout and organization
  • Inkflow vector ink system
  • Typing with various fonts
  • Photo import for backgrounds
  • Project planning and storyboarding
Features
Read full description

We love index cards. We use them a lot. They are a versatile and surprisingly powerful tool for all kinds of tasks. From brainstorming to storyboards, to planning entire projects, they have a place in your workflow. Cardflow captures the ease and flexibility of paper index cards and brings that experience to the iPad. Rather than impose a rigid structure up front, Cardflow allows you to lay things out however you like, and organize them in the way that makes sense to you. Jot down ideas or sketch diagrams on cards and arrange them on a large board. Write and draw using the buttery smooth Inkflow vector ink system, or type in a variety of fonts. You can even snap photos of actual cards to use as a background. Turbocharge your workflow today! Whether you are drafting story boards for a movie, laying out the plot and characters for your novel, or learning a new language, Cardflow has a place in your toolbox. Have all the fun of using index cards, without the forest-pulping guilt of paper. EDUCATORS: Cardflow+ qualifies for Apple's Volume Purchase Program. Purchase it in quantities of 20 or more at a discount from Apple's VPP site. HOW TO TRANSFER FILES FROM CARDFLOW Cardflow+ is installed as a separate App. To transfer a file from Cardflow to Cardflow+: 1. Tap on the file name in the Cardflow Gallery. 2. Tap "Transfer" in the context menu. 3. Select Cardflow+ from the list of Apps. Cardflow is perfect for: + Storyboards for videos or movies + Studying for an exam + Learning a new language + Writing the plot for a novel or book + Organizing weddings, parties, and other events + Corporate training + Project management + Agile, Scrum, and other methodologies + Group brainstorming + Writing your daily goals and to-dos + And much more! CREATIVE TOOLS FOR THE ULTIMATE CREATIVITY DEVICE We strongly believe that the iPad is not just a consumption device; It's a creativity device. Thanks for supporting us in our journey of building Creative Apps like Cardflow. We hope you enjoy using it! -- The App Makers @ Qrayon

About

KnowledgeBase Builder

Organize and search text documents and web pages with links within a mind map structure. Automatically create mind maps from text, import Wikipedia articles, and export your knowledge base as HTML. Also functions as a flowcharting tool.

Highlights
  • Save text documents and web pages
  • Full-text search
  • Organize with mind maps
  • Automatic mind map creation
  • Wikipedia import
  • Export to HTML
  • Flowcharting tool
Features
Read full description

The InfoRapid KnowledgeBase Builder is an excellent tool for Knowledge Management. You can save text documents and web pages with all formattings and links in your knowledge base and perform a full text search in it. Since every document is attached as a text note to a mindmap item, you can organize them perfectly in a large mindmap. This mindmap is browsable, so you will never lose perspective even with thousands of documents. All items are stored in a reliable local SQLite database. The app includes many other outstanding features such as the automatic creation of mindmaps from text documents, the import of Wikipedia articles into your mindmap and much more. You can even export your knowledge base as a formatted html document. And that's not all. The InfoRapid KnowledgeBase Builder is also a famous flowcharting tool. You can either create your flowcharts manually or generate them automatically from pseudo code. And there are a thousand more things you can do with the app.

Screenshots

KnowledgeBase Builder4 screens

Verdict

The call

The clearest difference is price: KnowledgeBase Builder at $8.99 against Cardflow+ by Qrayon's $14.99. KnowledgeBase Builder also leads on review sentiment (91% vs 69%) and device support (3 vs 1). Cardflow+ by Qrayon's advantage is ratings volume (1.5K vs 24) and update cadence (every 6 days vs fortnightly). On rating, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Cardflow+ by Qrayon costs $14.99 and KnowledgeBase Builder $8.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.6 for Cardflow+ by Qrayon against 4.7 for KnowledgeBase Builder. That said, the two scores are not equally well evidenced: Cardflow+ by Qrayon has 1.5K ratings behind it against 24, so its average is the more settled of the two. Written reviews are what separate them: 69% of Cardflow+ by Qrayon's written reviews are positive against 91% of KnowledgeBase Builder's.

UpkeepUpdate frequency

Cardflow+ by Qrayon ships an update every 6 days, KnowledgeBase Builder fortnightly. The most recent releases landed on September 23, 2026 and September 7, 2026 respectively.

Scorecard5 real differences · 5 level
Cardflow+ by Qrayon versus KnowledgeBase Builder: the parameters behind the verdict, then further details
ParameterCardflow+ by QrayonKnowledgeBase Builder
Price$14.99$8.99 — better
Rating4.6 (1.5K ratings)4.7 (24 ratings) — better
Positive reviews69.4% of reviews90.9% of reviews — better
Number of ratings1.5K — better24
Update frequencyEvery 6 days — betterFortnightly
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPadiPhone, iPad, iPod — better
Requires iOS15.615.0 — better
Further details — not scored
Size16 MB21 MB
Age rating17+4+
DeveloperQrayon, LLCIngo Straub

Customer experience

Cardflow+ by Qrayon

All ratings1,470 ratings
Positive90.1%
Neutral4.6%
Negative5.3%
Written reviews255 reviews
Positive69.4%
Neutral11.8%
Negative18.8%

KnowledgeBase Builder

All ratings24 ratings
Positive95.8%
Neutral0.0%
Negative4.2%
Written reviews22 reviews
Positive90.9%
Neutral0.0%
Negative9.1%

Bugs and requests

Cardflow+ by Qrayon

Reported bugs

3 issues
  • Cards randomly losing content
  • Exporting issues with images and links
  • Inconsistent behavior when flipping cards

Requested features

6 requests
  • Add a study/quiz mode for flashcards
  • Improve syncing and cloud integration
  • Allow multiple images per card
  • Provide more customization options for text and formatting
  • Implement a highlighter tool separate from the pen
Show 1 more
  • Add the ability to lock or protect boards

KnowledgeBase Builder

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Cardflow+ by Qrayon

No in-app purchases

None

KnowledgeBase Builder

No in-app purchases

Questions

Is Cardflow+ by Qrayon free?
Cardflow+ by Qrayon costs $14.99, with no in-app purchases.
Is KnowledgeBase Builder free?
KnowledgeBase Builder costs $8.99, with no in-app purchases.
Which has better reviews, Cardflow+ by Qrayon or KnowledgeBase Builder?
KnowledgeBase Builder is rated higher. Cardflow+ by Qrayon averages 4.6 out of 5 from 1.5K ratings, while KnowledgeBase Builder averages 4.7 from 24 ratings.
Do Cardflow+ by Qrayon or KnowledgeBase Builder have ads?
Neither Cardflow+ by Qrayon nor KnowledgeBase Builder shows ads.
Which is updated more often, Cardflow+ by Qrayon or KnowledgeBase Builder?
Cardflow+ by Qrayon ships an update every 6 days, and KnowledgeBase Builder fortnightly. Most recently, Cardflow+ by Qrayon was updated on September 23, 2026 and KnowledgeBase Builder on September 7, 2026.

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