# Nyquist App vs Control Systems Engineering

The clearest difference is in-app purchases: Nyquist App at none against Control Systems Engineering's 6. Nyquist App also leads on device support (3 vs 1) and iOS requirement (13.0 vs 17.0). Control Systems Engineering's advantage is update cadence (every 3 months vs every 10 months). On price and ads there is nothing between them.

Both are free to download. Control Systems Engineering sells 6 in-app purchases, starting at $9.99 per month. Nyquist App asks for nothing beyond the download.

Nyquist App ships an update every 10 months, Control Systems Engineering every 3 months. Both last shipped on September 14, 2026.

## The numbers

| Metric | Nyquist App | Control Systems Engineering |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nyquist-app/id1444291209/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 months | **Every 3 months** |
| Monetization | Free | — |
| Size | 22 MB | 18 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Patricia Pauli](https://appshunter.io/developer/1587769862) | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) |

## 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


### Control Systems Engineering

[App page](https://appshunter.io/ios/app/control-systems-engineering/id6739731886)

**Features:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Month | $9.99 | per month |
| 6 Months | $19.99 | per 6 months |
| 1 Year | $29.99 | per year |
| 1500 | $0.99 | one-time |
| 3500 | $1.99 | one-time |
| 9000 | $3.99 | one-time |


## Frequently asked questions

### Is Nyquist App free?

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

### Is Control Systems Engineering free?

Control Systems Engineering is free to download, with in-app purchases available.

### Do Nyquist App or Control Systems Engineering have ads?

Neither Nyquist App nor Control Systems Engineering shows ads.

### Which is updated more often, Nyquist App or Control Systems Engineering?

Nyquist App ships an update every 10 months, and Control Systems Engineering every 3 months. Most recently, Nyquist App was updated on September 14, 2026 and Control Systems Engineering on September 14, 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.*