Comparison

Relativity Widget vs SFX Scientific Calc Premium

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

Head to head
About

Relativity Widget

Visualize Einstein's theories of relativity directly on your home screen. Choose between Special Relativity to see time dilation in a spaceship or General Relativity to observe time differences near a black hole.

Highlights
  • Special Relativity visualization
  • General Relativity visualization
  • Time dilation display
  • Home screen integration
  • Customizable speed/distance settings
Features
Read full description

Relativity Widget allows you to visualise Einstein's theories of relativity right on your home screen. Two modes : • Special Relativity: imagine that you are in a spaceship travelling at a chosen speed. If you travel fast enough, time will pass differently on earth... • General Relativity: you are on earth while a friend of yours went on a journey, in a spaceship, at a chosen distance to a Schwarzschild black hole. If you are close enough, time will pass differently in the spaceship... Relativity Widget clocks represent the difference in time flow, since midnight, between a high speed / high gravity experiencing reference frame and a low speed / gravity one, according to Einstein's theory of relativity.

About

SFX Scientific Calc Premium

This scientific calculator offers advanced functions for academic, scientific, and engineering needs. It supports basic arithmetic, memory storage, statistical calculations, and various mathematical functions. The interface mimics a popular Casio model for ease of use.

Highlights
  • Basic arithmetic operations
  • Constant and volatile memory storage
  • Fraction and percentage calculations
  • Linear regression and statistics
  • Number base conversions (Binary, Octal, Decimal, Hexadecimal)
  • Trigonometric, hyperbolic, and logarithmic functions
  • Formula calculations
Features
Read full description

SFX Calc Premium gives students and engineers a familiar handheld-style scientific calculator on iPhone, iPad, and Mac. From quick arithmetic to statistics and engineering formulas, it keeps advanced calculations in a practical, customizable layout. FEATURES • Scientific functions: trigonometric, hyperbolic, logarithmic, exponential, power, and root • Engineering notation with SI prefixes • Fraction and percentage calculations • Linear regression and statistical calculations • Binary, octal, decimal, and hexadecimal modes • Fixed-constant calculations for repeated operations • One persistent memory plus 10 temporary memory registers • Built-in formulas, including the quadratic formula, standard normal distribution probabilities, and engineering calculations • Configurable 10- or 13-digit display and exponent formats • Copy and paste support for faster workflows • A familiar keypad with customizable layout options • Ads free and no pop-up review Ideal for coursework, laboratories, electronics, mathematics, science, and everyday engineering work.

Screenshots

Relativity Widget4 screens
SFX Scientific Calc Premium4 screens

Verdict

The call

The clearest difference is price: Relativity Widget at Free against SFX Scientific Calc Premium's $5.99. Relativity Widget also leads on rating (5.0 vs 4.3). SFX Scientific Calc Premium's advantage is update cadence (monthly vs every 6 months) and device support (4 vs 2). On ads, in-app purchases and iOS requirement 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

Relativity Widget is free to download; SFX Scientific Calc Premium costs $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Relativity Widget holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

UpkeepUpdate frequency

Relativity Widget ships an update every 6 months, SFX Scientific Calc Premium monthly. Both last shipped on October 10, 2026.

Scorecard6 real differences · 4 level
Relativity Widget versus SFX Scientific Calc Premium: the parameters behind the verdict, then further details
ParameterRelativity WidgetSFX Scientific Calc Premium
PriceFree — better$5.99
Rating5.0 (1 ratings) — better4.3 (3 ratings)
Positive reviews—80.0% of reviews
Number of ratings13 — better
Update frequencyEvery 6 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPodiPhone, iPad, iPod, Mac — better
Requires iOS14.014.0
Further details — not scored
Size1 MB16 MB
Age rating4+4+
DeveloperEliott MorgenszternWai Kwong Lee

Customer experience

Relativity Widget

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

SFX Scientific Calc Premium

All ratings3 ratings
Positive66.7%
Neutral33.3%
Negative0.0%
Written reviews5 reviews
Positive80.0%
Neutral20.0%
Negative0.0%

In-app purchases

None

Relativity Widget

No in-app purchases

None

SFX Scientific Calc Premium

No in-app purchases

Questions

Is Relativity Widget free?
Relativity Widget is free to download, with no in-app purchases.
Is SFX Scientific Calc Premium free?
SFX Scientific Calc Premium costs $5.99, with no in-app purchases.
Which has better reviews, Relativity Widget or SFX Scientific Calc Premium?
Relativity Widget is rated higher. Relativity Widget averages 5.0 out of 5 from 1 ratings, while SFX Scientific Calc Premium averages 4.3 from 3 ratings.
Do Relativity Widget or SFX Scientific Calc Premium have ads?
Neither Relativity Widget nor SFX Scientific Calc Premium shows ads.
Which is updated more often, Relativity Widget or SFX Scientific Calc Premium?
Relativity Widget ships an update every 6 months, and SFX Scientific Calc Premium monthly. Most recently, Relativity Widget was updated on October 10, 2026 and SFX Scientific Calc Premium on October 10, 2026.

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