# Trigonometry Hong Kong vs Grade 9 Math Practice

The clearest difference is price: Trigonometry Hong Kong at Free against Grade 9 Math Practice's $0.49. Grade 9 Math Practice's advantage is update cadence (fortnightly vs every 34 months) and iOS requirement (13.0 vs 15.6). On ads, in-app purchases and device support there is nothing between them.

Trigonometry Hong Kong is free to download; Grade 9 Math Practice costs $0.49 up front. Neither carries in-app purchases, so what you see is what you pay.

Trigonometry Hong Kong ships an update every 34 months, Grade 9 Math Practice fortnightly. The most recent releases landed on October 21, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Trigonometry Hong Kong | Grade 9 Math Practice |
| --- | --- | --- |
| Price | **Free** | $0.49 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/trigonometry-hong-kong/id1557131849/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 34 months | **Fortnightly** |
| Monetization | Free | — |
| Size | 4 MB | 25 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [See Yan Wong](https://appshunter.io/developer/1453422332) | [Manish Kumar](https://appshunter.io/developer/1854995154) |

## What reviewers say

### Trigonometry Hong Kong

[App page](https://appshunter.io/ios/app/trigonometry-hong-kong/id1557131849)

This app provides a comprehensive guide to trigonometric formulas essential for Hong Kong university entrance exams. It covers a wide range of formulas, from basic sine and cosine to more advanced compound and subsidiary angle identities.

**Highlights:** Compound Angle Formulas, Subsidiary Angle Formulas, Double Angle Formulas, Triple Angle Formulas, Half Angle Formulas, Product-To-Sum Formulas, Sum-To-Product Formulas

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

**In-app purchases:** none


### Grade 9 Math Practice

[App page](https://appshunter.io/ios/app/grade-9-math-practice/id6757458527)

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

**In-app purchases:** none


## Frequently asked questions

### Is Trigonometry Hong Kong free?

Trigonometry Hong Kong is free to download, with no in-app purchases.

### Is Grade 9 Math Practice free?

Grade 9 Math Practice costs $0.49, with no in-app purchases.

### Do Trigonometry Hong Kong or Grade 9 Math Practice have ads?

Neither Trigonometry Hong Kong nor Grade 9 Math Practice shows ads.

### Which is updated more often, Trigonometry Hong Kong or Grade 9 Math Practice?

Trigonometry Hong Kong ships an update every 34 months, and Grade 9 Math Practice fortnightly. Most recently, Trigonometry Hong Kong was updated on October 21, 2026 and Grade 9 Math Practice on October 25, 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.*