# Third grade Math vs Sub System

The clearest difference is price: Third grade Math at $2.99 against Sub System's $30.00. Sub System's advantage is update cadence (every 10 days vs every 28 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Third grade Math costs $2.99 and Sub System $30.00 up front. Neither carries in-app purchases, so what you see is what you pay.

Third grade Math ships an update every 28 months, Sub System every 10 days. The most recent releases landed on October 10, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Third grade Math | Sub System |
| --- | --- | --- |
| Price | **$2.99** | $30.00 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 28 months | **Every 10 days** |
| Monetization | — | Paid |
| Size | 17 MB | 48 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sergey Malugin](https://appshunter.io/developer/562782409) | [sebastian rivas](https://appshunter.io/developer/506708461) |

## What reviewers say

### Third grade Math

[App page](https://appshunter.io/ios/app/third-grade-math-subtraction/id1271515324)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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


## Frequently asked questions

### Is Third grade Math free?

Third grade Math costs $2.99, with no in-app purchases.

### Is Sub System free?

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

### Do Third grade Math or Sub System have ads?

Neither Third grade Math nor Sub System shows ads.

### Which is updated more often, Third grade Math or Sub System?

Third grade Math ships an update every 28 months, and Sub System every 10 days. Most recently, Third grade Math was updated on October 10, 2026 and Sub System 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.*