Comparison

Free42 vs TechniCalc Calculator

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

Head to head
About

Free42

This app is a faithful open-source simulation of the HP-42S scientific calculator and its associated printer. It offers a complete rewrite without requiring original ROM images, allowing users to run existing programs on their mobile devices.

Highlights
  • HP-42S calculator simulation
  • HP-82240 printer simulation
  • Open-source project
  • Runs original HP-42S programs
  • No ROM image required
  • Customizable skins
Features
Read full description

Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer. It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image. Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2. All third-party code used in Free42 is either in the public domain, or licensed under terms compatible with GPLv2, or used with the authors' permission.

About

TechniCalc Calculator

This app offers a modern, intuitive interface for complex calculations, supporting scientific, engineering, and advanced mathematical functions. It allows natural equation entry, provides a formula book, and includes unit and currency converters. Available across Apple devices, it caters to students and professionals needing a powerful calculation tool.

Highlights
  • Natural equation entry
  • Advanced math engine
  • Formula book and equations
  • Unit and currency converter
  • Statistics mode
  • Equation solvers
  • Supports multiple Apple devices
Features
Read full description

TechniCalc is every bit functional as it is beautiful. The modern interface that makes a clean break from traditional pocket calculators. Equations are entered in a natural way, adhering to every detail of hand-written maths. The advanced maths engine also makes this the only calculator you'll ever need. ◉ FEATURES ▸ Runs on iPhone, iPad, and macOS - with an Apple Watch companion ▸ Dark mode ▸ Supports split screen and wireless keyboards ▸ Shows the full equation as you type ▸ Basic calculations (+, -, ×, ÷, %) ▸ Brackets ▸ Square and cubic roots ▸ Exponents and logarithms ▸ Trigonometry (sin, cos, tan) ▸ Degrees, radians, and gradians ▸ Constants (pi, e, and over 100 other physical constants) ▸ Formula book and equations ▸ Calculation history ▸ Unit converter ▸ Currency converter ▸ Statistics mode ◉ ADVANCED MATHS ▸ Almost unlimited number sizes - over 1,000,000 factorial ▸ Square roots and logarithms with any base ▸ Factorial, nPr, nCr, and gamma ▸ Hyperbolic trigonometry (sinh, cosh, tanh) ▸ Vectors and matrices ▸ Imaginary and complex numbers ▸ Series sums and products ▸ Numerical integration and differentiation ▸ Binary, octal, and hexadecimal ▸ Programmer mode ◉ EQUATION SOLVERS ▸ Quadratic ▸ Cubic ▸ Systems of 2 and 3 linear equations ▸ Root finder

Screenshots

Free423 screens
TechniCalc Calculator4 screens

Verdict

The call

The clearest difference is price: Free42 at Free against TechniCalc Calculator's $7.99. Free42 also leads on in-app purchases (none vs 4) and update cadence (weekly vs monthly). On rating, ads 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

Free42 is free to download; TechniCalc Calculator costs $7.99 up front. TechniCalc Calculator sells 4 one-off in-app purchases. Free42 asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Free42 against 4.7 for TechniCalc Calculator. Both are backed by a comparable volume of ratings — 288 and 84 respectively. Written reviews are what separate them: 94% of Free42's written reviews are positive against 85% of TechniCalc Calculator's.

UpkeepUpdate frequency

Free42 ships an update weekly, TechniCalc Calculator monthly. Both last shipped on November 13, 2026.

Scorecard7 real differences · 3 level
Free42 versus TechniCalc Calculator: the parameters behind the verdict, then further details
ParameterFree42TechniCalc Calculator
PriceFree — better$7.99
Rating4.8 (288 ratings) — better4.7 (84 ratings)
Positive reviews94.4% of reviews — better84.6% of reviews
Number of ratings288 — better84
Update frequencyWeekly — betterMonthly
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, Mac, Apple Watch — better
Requires iOS15.0 — better17.0
Further details — not scored
Size9 MB31 MB
Age rating4+4+
DeveloperThomas OkkenJacob Parker

Customer experience

Free42

All ratings288 ratings
Positive93.8%
Neutral2.4%
Negative3.8%
Written reviews178 reviews
Positive94.4%
Neutral1.7%
Negative3.9%

TechniCalc Calculator

All ratings84 ratings
Positive90.5%
Neutral6.0%
Negative3.6%
Written reviews39 reviews
Positive84.6%
Neutral12.8%
Negative2.6%

User reviews

Free42

From 288 App Store ratings

What we love

  • 🚀 Faithful reproduction of HP42S
  • 👍 Identical to physical calculator
  • 👍 Runs all original programs
  • 👍 Convenient to have on phone
  • 👍 Haptic feedback on button presses

Room to improve

  • 🐛 Screen not filling entire display on newer devices
  • 🔇 Configurable key click sound missing
  • 🔇 Lack of loud click sound feedback

TechniCalc Calculator

From 84 App Store ratings

What we love

  • ✨ Beautiful and clean UI
  • 🚀 Powerful and versatile functionality
  • 👍 Intuitive and easy to use
  • 💡 Extensive features for scientific and basic use
  • 👨‍💻 Responsive and dedicated developer

Room to improve

  • 🐛 Interface scaling issues on iPad (split screen/windowed mode)
  • 🐛 UI elements (keypad, sidebar) become enormous when resized
  • 🐛 Calculations get squished at the top of the window
  • 🐛 Matrices overlap on themselves when resized
  • 🐛 Text too small and light on iPad

Bugs and requests

Free42

Reported bugs

2 issues
  • Occasional issues with Solver function
  • Store and Recall functions not working properly

Requested features

3 requests
  • Display all registers (X, Y, Z, T, Last X) simultaneously
  • Ability to share/transfer programs between devices
  • Improved use of screen real estate on larger displays

TechniCalc Calculator

Reported bugs

18 issues
  • Interface scaling issues on iPad (split screen/windowed mode)
  • UI elements (keypad, sidebar) become enormous when resized
  • Calculations get squished at the top of the window
  • Matrices overlap on themselves when resized
  • Text too small and light on iPad
Show 13 more
  • Unit converter is time-consuming to change units
  • Matrix dimensions are not always possible (e.g., 3x2)
  • Lacks basic matrix functions like reducedRowEchelon
  • Complicated to use for some matrix operations
  • No real instruction manual, reference section incomplete
  • Inconsistencies in signs with decimal numbers (magnitude correct, sign always positive)
  • Some calculations can be slow after currency update
  • Real and imaginary breakout functions have strange behavior
  • Window size cannot be changed on macOS
  • Cannot force quit on macOS, requires restart
  • Not easily findable on macOS
  • No way to leave a second tip for the developer
  • Resent not being able to email the developer directly

Requested features

15 requests
  • Functionality on Apple Watch
  • Option to change divide sign to /
  • Multi-line history on the top
  • Color coding for grouped buttons
  • More interface customization
Show 10 more
  • Option to color the background of calculator buttons
  • Widget for quick access
  • Favorites menu for unit conversions
  • Syncing of saved equations and settings across devices
  • Easier way to solve for a parameter in an equation without initial guesses
  • Export operations as LaTeX
  • Decimal to mixed number form conversion
  • Unlock different background colors/themes and app icons
  • Adjust font size to be bolder and larger on iPad
  • Improved functionality in low light and outside

In-app purchases

None

Free42

No in-app purchases

4 purchases

TechniCalc Calculator

One-time4
  • Every Little Helps$0.99
  • Coffee-Sized Tip$2.99
  • Lunch-Sized Tip$4.99
Show 1 more
  • Pizza-Sized Tip$9.99

Questions

Is Free42 free?
Free42 is free to download, with no in-app purchases.
Is TechniCalc Calculator free?
TechniCalc Calculator costs $7.99, and also offers in-app purchases.
Which has better reviews, Free42 or TechniCalc Calculator?
Free42 is rated higher. Free42 averages 4.8 out of 5 from 288 ratings, while TechniCalc Calculator averages 4.7 from 84 ratings.
Do Free42 or TechniCalc Calculator have ads?
Neither Free42 nor TechniCalc Calculator shows ads.
Which is updated more often, Free42 or TechniCalc Calculator?
Free42 ships an update weekly, and TechniCalc Calculator monthly. Most recently, Free42 was updated on November 13, 2026 and TechniCalc Calculator on November 13, 2026.

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