# Sub System vs Fraction Calculator Plus +

The clearest difference is price: Fraction Calculator Plus + at Free against Sub System's $30.00. Sub System's advantage is ads (none vs shown) and update cadence (every 10 days vs every 14 months). On in-app purchases, monetization model, device support and iOS requirement there is nothing between them.

Fraction Calculator Plus + is free to download; Sub System costs $30.00 up front. Neither carries in-app purchases, so what you see is what you pay.

Sub System ships an update every 10 days, Fraction Calculator Plus + every 14 months. The most recent releases landed on October 7, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Sub System | Fraction Calculator Plus + |
| --- | --- | --- |
| Price | $30.00 | **Free** |
| Rating | — | **[4.3 (12 ratings)](https://appshunter.io/ios/app/fraction-calculator-plus-plus/id6749723037/reviews)** |
| Number of ratings | — | **12** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 10 days** | Every 14 months |
| Monetization | Paid | Paid |
| Size | 48 MB | 71 MB |
| Requires iOS | **13.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [sebastian rivas](https://appshunter.io/developer/506708461) | [JanoGroup LLC](https://appshunter.io/developer/1781461557) |

## What reviewers say

### Sub System

[App page](https://appshunter.io/ios/app/sub-system/id1533524994)

This app allows audio engineers and sound designers to visualize sound pressure levels and their interactions. Users can place virtual speakers and microphones, manipulate them with touch gestures, and observe colorful graphs of SPL and frequency response to understand acoustical summation.

**Highlights:** Virtual speaker placement, Sound pressure level visualization, Frequency response graphs, Virtual microphone simulation, Touch-based manipulation, Acoustical summation understanding

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

**In-app purchases:** none


### Fraction Calculator Plus +

[App page](https://appshunter.io/ios/app/fraction-calculator-plus-plus/id6749723037)

This app simplifies complex fraction math with step-by-step visual guidance. It handles various operations, conversions, and simplifications, making it ideal for students, teachers, and professionals. It works offline and offers a user-friendly interface for all your fraction calculation needs.

**Highlights:** Add, subtract, multiply, divide fractions, Mixed number and improper fraction support, Visual fraction representation, Step-by-step solution explanations, Simplify fractions automatically, Convert between decimals and fractions, Offline functionality

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

**In-app purchases:** none


## Frequently asked questions

### Is Sub System free?

Sub System costs $30.00, with no in-app purchases.

### Is Fraction Calculator Plus + free?

Fraction Calculator Plus + is free to download, with no in-app purchases.

### Do Sub System or Fraction Calculator Plus + have ads?

Fraction Calculator Plus + shows ads; Sub System does not.

### Which is updated more often, Sub System or Fraction Calculator Plus +?

Sub System ships an update every 10 days, and Fraction Calculator Plus + every 14 months. Most recently, Sub System was updated on October 7, 2026 and Fraction Calculator Plus + on October 24, 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.*