Comparison

ThetaCalc vs XLII

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

Head to head
About

ThetaCalc

This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.

Highlights
  • Reverse Polish Notation (RPN) calculator
  • User-programmable functions
  • JavaScript equation support
  • Extensible functionality
Features
Read full description

ThetaCalc is a RPN (Reverse Polish Notation) calculator which can be extended by functions and equations programmed by the user in JavaScript.

About

XLII

Features
Read full description

XLII - Explore Numbers and Numerals help you learn about, discover, and explore number and numerals from around the world, ranging from familiar Roman numerals to the ancient Kharoṣṭhī script. You even can use your camera to scan numbers and convert them to an interesting output format.  To achieve full immersion, use the XLII Clock widget to display the current date and time in a number format of your choosing directly in your Home Screen. XLII - Explore Numbers and Numerals supports: - Arabic numerals (naturally) - Roman numerals - Japanese numerals (including financial notation) - Babylonian Cuneiform numerals (base 60) - Aegean numerals (Linear B script) - Chinese counting rods (籌) - Egyptian Hieroglyphs - Suzhou numbers (蘇州碼子) - Phoenician numbers - Kharoṣṭhī numerals - Brahmi numerals - Glagolitic numerals - Cyrillic numerals - Ge'ez numbers - Sundanese numbers - Tibetan numbers - Mongolian numbers - hexadecimal, binary, octal, vigesimal, etc. - spell-out notation for many languages Most formats are also accepted as input, e.g. you can convert from Roman to Cyrillic, from Ge'ez to binary, or from Japanese to Babylonian. Some (ancient) formats don't support large numbers.

Screenshots

ThetaCalc4 screens
XLII3 screens

Verdict

The call

The clearest difference is update cadence: ThetaCalc at every 3 months against XLII's every 9 months. On price, 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

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

ThetaCalc ships an update every 3 months, XLII every 9 months. Both last shipped on November 3, 2026.

Scorecard1 real difference · 9 level
ThetaCalc versus XLII: the parameters behind the verdict, then further details
ParameterThetaCalcXLII
PriceFreeFree
Rating4.3 (4 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings4 — better—
Update frequencyEvery 3 months — betterEvery 9 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPadiPhone, iPad, Mac — better
Requires iOS17.617.6
Further details — not scored
Size1 MB15 MB
Age rating4+4+
DeveloperFelix Stehlitelethon k.k.

In-app purchases

None

ThetaCalc

No in-app purchases

None

XLII

No in-app purchases

Questions

Is ThetaCalc free?
ThetaCalc is free to download, with no in-app purchases.
Is XLII free?
XLII is free to download, with no in-app purchases.
Do ThetaCalc or XLII have ads?
Neither ThetaCalc nor XLII shows ads.
Which is updated more often, ThetaCalc or XLII?
ThetaCalc ships an update every 3 months, and XLII every 9 months. Most recently, ThetaCalc was updated on November 3, 2026 and XLII on November 3, 2026.

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