Comparison

i41CX+ vs Klaro Cards

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

Head to head
About

i41CX+

This advanced RPN scientific calculator offers workstation-class Computer Algebra System (CAS) capabilities, going beyond traditional replicas. It provides access to an extensive library of modules and programs, enhanced with iOS features, customizable skins, and iCloud support for seamless data management.

Highlights
  • RPN logic with 4-element stack
  • Extensive memory registers
  • Over 400 built-in functions
  • Computer Algebra System (CAS)
  • Virtual thermal printer/plotter
  • Access to HP-41 module library
  • Customizable skins and keyboard overlays
Read full description

i41CX+ is an advanced programmable and expandable RPN scientific calculator with a virtual thermal printer/plotter and workstation-class CAS capabilities that is far beyond a mere replica of the original. In addition to being functionally equivalent to the world-renowned HP-41CX and providing access to its entire library of modules and programs, i41CX+ is enhanced with iOS and hardware features, keyboard overlays, rich set of import and export capabilities, traditional and upbeat diverse set of skins, complete color control, iCloud support, and much more. The i41CX+ CAS is a full implementation of REDUCE. It's like having Mathematica or the computational engine of Wolfram Alpha in your pocket and, best of all, it runs natively so no internet connection is required. The CAS is fully programmable and provides the ability to reuse previous results in computations. Moreover, the CAS has full access to the calculator registers so it is possible to combine RPN programs with CAS programs. This is the finest and most powerful scientific/engineering/financial calculator for iOS devices bar none. CALCULATOR FEATURES: • RPN logic with a 4 element deep memory stack • 319 main and 600 extended memory registers • Over 400 built-in functions, including over 100 functions created specifically for i41CX+ • Time, calendar, alarm, and stopwatch functions • Four module ports provide access to HP-41 expansion pacs • Rich set of functions and algorithms: numerical, mathematical, statistical, complex, matrix, numerical integration, curve fitting, solutions to equations, and much more • Powerful, flexible, and programmable Computer Algebra System (CAS) supporting symbolic, arbitrary precision, scalar, vector and matrix algebra calculations, 2D/3D plotting, and much more • Full-screen text editor with configurable font style and size, color scheme, a user configurable macro keyboard, and a numerical keyboard • Access to the entire HP-41 library of solutions for science, mathematics, statistics, engineering, business, financial, surveying, medicine, real estate, and many other domains • Programmable - virtually unlimited number of lines • User definable keyboard • Ability to operate the calculator using a Bluetooth keyboard • Device integration: external display mirroring, copy and paste, in-app mail, system keyboard, GPS, accelerometer, digital compass, time and date synchronization, AirPrint, and much more • Virtually unlimited data and program storage capacity using the device's flash memory for local storage • Import/export data, programs, overlays, modules, etc. via the web, email, and iTunes file sharing • iCloud syncing of files and preference settings • iOS 8 Notification Center widget • 43 available keyboard overlays and support for user created overlays • Sound support including synthetic tones and interface sounds • Support for calculator skins and optional mini stack display • Adjustable calculator speed, sound volume, and display colors • Usage & Examples table with usage tips and examples • Quick Reference Guide of all built-in functions • CAS Quick Reference with all built-in functions, operators, switches, and packages • Beautiful and clean user interface PRINTER FEATURES: • Support for printing, plotting, graphics, and special characters • User configurable and programmable print color • Export printer output via email, clipboard, or AirPrint • Ability to save a JPEG image of the paper roll to the device's photo album *********************************************************** A comprehensive FAQ and Mini-Manual are available at http://alsoftiphone.com/i41CXplus. Please don't hesitate to use the "Contact Us" link there if you cannot find the answers or information that you seek. Thank you.

About

Klaro Cards

Features
Read full description

Escape the world of inefficient conversations, unstructured documents, and lengthy data files. Klaro Cards teaches you how to collect, enrich, act on, and distribute information that matters. So that you can focus on what really matters.

Screenshots

i41CX+4 screens
Klaro Cards4 screens

Verdict

The call

The clearest difference is price: Klaro Cards at Free against i41CX+'s $24.99. i41CX+'s advantage is iOS requirement (13.0 vs 15.6). On update cadence, ads, in-app purchases and device support 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

Klaro Cards is free to download; i41CX+ costs $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

i41CX+ ships an update every 5 weeks, Klaro Cards every 2 months. The most recent releases landed on September 23, 2026 and September 19, 2026 respectively.

Scorecard2 real differences · 8 level
i41CX+ versus Klaro Cards: the parameters behind the verdict, then further details
Parameteri41CX+Klaro Cards
Price$24.99Free — better
Rating4.8 (106 ratings) — better—
Positive reviews91.3% of reviews—
Number of ratings106 — better—
Update frequencyEvery 5 weeks — betterEvery 2 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.6
Further details — not scored
Size123 MB34 MB
Age rating4+4+
DeveloperAntonio LaganaEnspirit

Bugs and requests

i41CX+

Reported bugs

2 issues
  • Issues with the 41Z math module producing garbled output
  • Scaling problems with overlays

Requested features

4 requests
  • Landscape mode for better button size
  • Haptic feedback for button presses
  • Ability to load and save programs/modules via cloud/email
  • Macros or scripting support

Klaro Cards

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

i41CX+

No in-app purchases

None

Klaro Cards

No in-app purchases

Questions

Is i41CX+ free?
i41CX+ costs $24.99, with no in-app purchases.
Is Klaro Cards free?
Klaro Cards is free to download, with no in-app purchases.
Do i41CX+ or Klaro Cards have ads?
Neither i41CX+ nor Klaro Cards shows ads.
Which is updated more often, i41CX+ or Klaro Cards?
i41CX+ ships an update every 5 weeks, and Klaro Cards every 2 months. Most recently, i41CX+ was updated on September 23, 2026 and Klaro Cards on September 19, 2026.

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