Comparison

iTurbo vs x

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

Head to head
About

iTurbo

This app simulates fluid dynamics by solving Navier-Stokes equations for 2D incompressible turbulence. It uses a direct numerical simulation method with Euler time stepping and Fourier space calculations for efficiency.

Highlights
  • Direct Numerical Simulation (DNS)
  • Navier-Stokes equation solver
  • 2D incompressible turbulence
  • Euler time stepping
  • Fourier space calculations
  • Vorticity field transformation
Features
Read full description

This application performs a Direct Numerical Simulation (DNS) where the Navier-Stokes equations are solved for two dimensional incompressible homogeneous turbulence. These equations are a set of nonlinear partial differential equations. The time stepping is performed with a simple Euler method where the time step is calculated so that the CFL number does not exceeds the given number (should be less than 0.8 otherwise the simulation blows up). The equations are solved in the Fourier space where the calculation of the nonlinear term transforms to a simple multiplication. The main CPU usage is consumed by transforming the vorticity field back and fourth between the Normal space where the time-stepping is performed and the Fourier space where the nonlinear term is calculated.

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

iTurbo3 screens
x4 screens

Verdict

The call

The clearest difference is update cadence: x at fortnightly against iTurbo's every 54 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

iTurbo ships an update every 54 months, x fortnightly. The most recent releases landed on September 29, 2026 and September 28, 2026 respectively.

Scorecard1 real difference · 8 level
iTurbo versus x: the parameters behind the verdict, then further details
ParameteriTurbox
PriceFreeFree
Rating5.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyEvery 54 monthsFortnightly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPod — betteriPhone
Requires iOS18.018.0
Further details — not scored
Size2 MB1 MB
Age rating4+4+
DeveloperManneTroll SolutionsFMILLET

In-app purchases

None

iTurbo

No in-app purchases

None

x

No in-app purchases

Questions

Is iTurbo free?
iTurbo is free to download, with no in-app purchases.
Is x free?
x is free to download, with no in-app purchases.
Do iTurbo or x have ads?
Neither iTurbo nor x shows ads.
Which is updated more often, iTurbo or x?
iTurbo ships an update every 54 months, and x fortnightly. Most recently, iTurbo was updated on September 29, 2026 and x on September 28, 2026.

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