# Signals and Systems vs Root Locus Plotter

The clearest difference is in-app purchases: Root Locus Plotter at none against Signals and Systems's 6. Root Locus Plotter also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.0). Signals and Systems's advantage is update cadence (every 5 weeks vs every 3 months). On price and ads there is nothing between them.

Both are free to download. Signals and Systems sells 6 in-app purchases, starting at $9.99 per month. Root Locus Plotter asks for nothing beyond the download.

Signals and Systems ships an update every 5 weeks, Root Locus Plotter every 3 months. The most recent releases landed on September 20, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Signals and Systems | Root Locus Plotter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 3 months |
| Size | 18 MB | 30 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) | [Sthefano Schiavon](https://appshunter.io/developer/1882733645) |

## What reviewers say

### Signals and Systems

[App page](https://appshunter.io/ios/app/signals-and-systems/id6739804680)

**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 |


### Root Locus Plotter

[App page](https://appshunter.io/ios/app/root-locus-plotter/id6760122394)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Signals and Systems free?

Signals and Systems is free to download, with in-app purchases available.

### Is Root Locus Plotter free?

Root Locus Plotter is free to download, with no in-app purchases.

### Do Signals and Systems or Root Locus Plotter have ads?

Neither Signals and Systems nor Root Locus Plotter shows ads.

### Which is updated more often, Signals and Systems or Root Locus Plotter?

Signals and Systems ships an update every 5 weeks, and Root Locus Plotter every 3 months. Most recently, Signals and Systems was updated on September 20, 2026 and Root Locus Plotter on September 16, 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.*