# 化學之書 vs HKDSE Physics Practice & Notes

The clearest difference is in-app purchases: 化學之書 at none against HKDSE Physics Practice & Notes's 4. HKDSE Physics Practice & Notes's advantage is update cadence (every 3 days vs every 3 weeks) and iOS requirement (15.6 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. HKDSE Physics Practice & Notes sells 4 in-app purchases, starting at $8.99 per month. 化學之書 asks for nothing beyond the download.

化學之書 ships an update every 3 weeks, HKDSE Physics Practice & Notes every 3 days. The most recent releases landed on October 27, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | 化學之書 | HKDSE Physics Practice & Notes |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Size | 55 MB | 145 MB |
| Requires iOS | 17.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [BUDDHIST HO NAM KAM COLLEGE](https://appshunter.io/developer/1532349038) | [Pickmy AI](https://appshunter.io/developer/1869516043) |

## What reviewers say

### 化學之書

[App page](https://appshunter.io/ios/app/id1512573867)

**Features:** Vision Pro support

**In-app purchases:** none


### HKDSE Physics Practice & Notes

[App page](https://appshunter.io/ios/app/hkdse-physics-practice-and-notes/id6781737430)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| DSE Physics Pro | $8.99 | per month |
| 180日 Pro 全功能 | $19.99 | one-time |
| 90日 Pro 全功能 | $19.99 | one-time |
| Pro 90天優惠 | $19.99 | one-time |


## Frequently asked questions

### Is 化學之書 free?

化學之書 is free to download, with no in-app purchases.

### Is HKDSE Physics Practice & Notes free?

HKDSE Physics Practice & Notes is free to download, with in-app purchases available.

### Do 化學之書 or HKDSE Physics Practice & Notes have ads?

Neither 化學之書 nor HKDSE Physics Practice & Notes shows ads.

### Which is updated more often, 化學之書 or HKDSE Physics Practice & Notes?

化學之書 ships an update every 3 weeks, and HKDSE Physics Practice & Notes every 3 days. Most recently, 化學之書 was updated on October 27, 2026 and HKDSE Physics Practice & Notes on November 5, 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.*