# Equation vs Signals and Systems

The clearest difference is price: Signals and Systems at Free against Equation's $1.99. Equation's advantage is in-app purchases (none vs 6) and device support (3 vs 1). On update cadence and ads there is nothing between them.

Signals and Systems is free to download; Equation costs $1.99 up front. Signals and Systems sells 6 in-app purchases, starting at $9.99 per month. Equation asks for nothing beyond the download.

Equation ships an update monthly, Signals and Systems every 5 weeks. The most recent releases landed on October 11, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Equation | Signals and Systems |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Monthly** | Every 5 weeks |
| Size | 30 MB | 18 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Om Prakash Chapagain](https://appshunter.io/developer/1618620262) | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) |

## What reviewers say

### Equation

[App page](https://appshunter.io/ios/app/equation-solver-pro/id1618982773)

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

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Equation free?

Equation costs $1.99, with no in-app purchases.

### Is Signals and Systems free?

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

### Do Equation or Signals and Systems have ads?

Neither Equation nor Signals and Systems shows ads.

### Which is updated more often, Equation or Signals and Systems?

Equation ships an update monthly, and Signals and Systems every 5 weeks. Most recently, Equation was updated on October 11, 2026 and Signals and Systems on October 7, 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.*