# Big Math vs Keywords Understanding Lite

The clearest difference is price: Keywords Understanding Lite at Free against Big Math's $1.99. Keywords Understanding Lite also leads on device support (3 vs 1). Big Math's advantage is update cadence (every 11 months vs every 68 months). On ads, in-app purchases and iOS requirement there is nothing between them.

Keywords Understanding Lite is free to download; Big Math costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Big Math ships an update every 11 months, Keywords Understanding Lite every 68 months. The most recent releases landed on November 10, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Big Math | Keywords Understanding Lite |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/keywords-understanding-lite/id1537440607/reviews)** |
| Number of ratings | — | **3** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 11 months** | Every 68 months |
| Monetization | — | Free |
| Size | 18 MB | 60 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Eaglet LLC](https://appshunter.io/developer/449193510) | [Aptus Speech and Language Therapy Limited](https://appshunter.io/developer/1482673468) |

## What reviewers say

### Big Math

[App page](https://appshunter.io/ios/app/big-math/id591862472)

**Features:** macOS Compatibility

**In-app purchases:** none


### Keywords Understanding Lite

[App page](https://appshunter.io/ios/app/keywords-understanding-lite/id1537440607)

This app offers a sample of speech and language therapy exercises focused on sentence comprehension. It helps users practice following directions, understanding basic concepts, and improving auditory and reading comprehension skills through interactive activities.

**Highlights:** Listening comprehension exercises, Reading comprehension exercises, Following directions (one/two-step, temporal, sequential), Basic concepts (size, color), Vocabulary understanding, Sample of full app features

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Big Math free?

Big Math costs $1.99, with no in-app purchases.

### Is Keywords Understanding Lite free?

Keywords Understanding Lite is free to download, with no in-app purchases.

### Do Big Math or Keywords Understanding Lite have ads?

Neither Big Math nor Keywords Understanding Lite shows ads.

### Which is updated more often, Big Math or Keywords Understanding Lite?

Big Math ships an update every 11 months, and Keywords Understanding Lite every 68 months. Most recently, Big Math was updated on November 10, 2026 and Keywords Understanding Lite on November 3, 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.*