# Nyquist App vs SISO Calculator

The clearest difference is update cadence: SISO Calculator at every 5 weeks against Nyquist App's every 10 months. SISO Calculator also leads on ratings volume (3 vs 1). On price, rating, ads and in-app purchases there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for Nyquist App against 5.0 for SISO Calculator. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

Nyquist App ships an update every 10 months, SISO Calculator every 5 weeks. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Nyquist App | SISO Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/nyquist-app/id1444291209/reviews) | [5.0 (3 ratings)](https://appshunter.io/ios/app/siso-calculator/id1548141101/reviews) |
| Number of ratings | 1 | **3** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 10 months | **Every 5 weeks** |
| Monetization | Free | Free |
| Size | 22 MB | 4 MB |
| Requires iOS | **13.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Patricia Pauli](https://appshunter.io/developer/1587769862) | [Deft Dynamics](https://appshunter.io/developer/1288783778) |

## What reviewers say

### Nyquist App

[App page](https://appshunter.io/ios/app/nyquist-app/id1444291209)

Practice the Nyquist stability criterion to determine closed-loop stability from open-loop frequency response. Developed for an introductory control engineering course, this app offers self-contained content for anyone interested in the topic.

**Highlights:** Nyquist stability criterion practice, Determine closed-loop stability, Frequency response analysis, Self-contained educational content, Developed for control engineering course

**Features:** macOS Compatibility

**In-app purchases:** none


### SISO Calculator

[App page](https://appshunter.io/ios/app/siso-calculator/id1548141101)

This app helps engineers and students understand System Dynamics and Controls. It offers an intuitive interface to quickly analyze controller and plant interactions in both time and frequency domains.

**Highlights:** System Dynamics analysis, Controls engineering, Intuitive interface, Time domain analysis, Frequency domain analysis, Controller interaction visualization

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Nyquist App free?

Nyquist App is free to download, with no in-app purchases.

### Is SISO Calculator free?

SISO Calculator is free to download, with no in-app purchases.

### Which has better reviews, Nyquist App or SISO Calculator?

Nyquist App and SISO Calculator are both rated 5.0 out of 5 on the App Store, from 1 and 3 ratings respectively.

### Do Nyquist App or SISO Calculator have ads?

Neither Nyquist App nor SISO Calculator shows ads.

### Which is updated more often, Nyquist App or SISO Calculator?

Nyquist App ships an update every 10 months, and SISO Calculator every 5 weeks. Most recently, Nyquist App was updated on November 2, 2026 and SISO Calculator on November 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*