Comparison

RPN Memory Calculator vs x

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

Head to head
About

RPN Memory Calculator

This application provides a straightforward reverse Polish notation (RPN) calculator with essential functions and memory operations. It also includes integrated unit conversions for various measurements, allowing for quick conversions directly within the app. The calculator remembers your session, preserving all registers and memory values for future use.

Highlights
  • Reverse Polish Notation (RPN) input
  • Seven core calculator functions
  • Memory operations
  • Integrated unit conversions (Speed, Mass, Temperature, Pressure)
  • Persistent state saving
  • Three visible registers
Features
Read full description

RPN Memory Calculator is a simple to use reverse polish notation calculator with seven functions and memory operations including a memory value display and three visible registers. This is not intended to be a full scientific function calculator, it is a handy implementation of basic calculator operations using RPN. The calculator also integrates unit conversions, so you can convert the value in the x register. This allows you to choose a type (Speed, Mass, Temperature, Pressure etc) and then pick a from and to type. The converted number can either be accepted back into the x register, or discarded. The calculator remembers state so that calculations you have been working on, with results stored in either the memory field or any of the registers, will still be present when re-open the app any time in the future. All registers, even the hidden ones above z are stored.

About

x

Features
Read full description

x-Cal is an ergonomic scientific calculator, in both portrait and landscape orientations, using RPN (c) Great for professional and educational use, it allows to quickly develop an understanding of register operations and basic programming Features fixed, scientific or engineer number formats, trigonometric and hyperbolic calculations in radians, degrees or grades, basic statistical computations, linear correlations, combinations, etc. Swipe on the top result display area to view the arithmetic register stack, tap on the top to display other registers such as storage register, statistical registers and program steps Record programs such as a quadratic equation solver, or display graphs to visualize functions y = f(x) At any time look, copy and paste text style computations into e-Mails, notes, etc.

Screenshots

RPN Memory Calculator3 screens
x4 screens

Verdict

The call

The clearest difference is in-app purchases: x at none against RPN Memory Calculator's 1. x also leads on update cadence (fortnightly vs every 4 months). RPN Memory Calculator's advantage is device support (3 vs 1) and iOS requirement (11.3 vs 18.0). On price and ads there is nothing between them.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. RPN Memory Calculator sells 1 one-off in-app purchase. x asks for nothing beyond the download.

UpkeepUpdate frequency

RPN Memory Calculator ships an update every 4 months, x fortnightly. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

Scorecard4 real differences ยท 4 level
RPN Memory Calculator versus x: the parameters behind the verdict, then further details
ParameterRPN Memory Calculatorx
PriceFreeFree
Positive reviews0.0% of reviewsโ€”
Update frequencyEvery 4 monthsFortnightly โ€” better
AdsNoNo
In-app purchasesYesNo โ€” better
MonetizationFreeโ€”
DevicesiPhone, iPad, iPod โ€” betteriPhone
Requires iOS11.3 โ€” better18.0
Further details โ€” not scored
Size8 MB1 MB
Age rating4+4+
DeveloperNeverest LimitedFMILLET

In-app purchases

1 purchases

RPN Memory Calculator

One-time1
  • Calculator Unit Conversions$0.99
None

x

No in-app purchases

Questions

Is RPN Memory Calculator free?
RPN Memory Calculator is free to download, with in-app purchases available.
Is x free?
x is free to download, with no in-app purchases.
Do RPN Memory Calculator or x have ads?
Neither RPN Memory Calculator nor x shows ads.
Which is updated more often, RPN Memory Calculator or x?
RPN Memory Calculator ships an update every 4 months, and x fortnightly. Most recently, RPN Memory Calculator was updated on October 24, 2026 and x on October 25, 2026.

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