# Book Context vs 灵线

The clearest difference is update cadence: 灵线 at every 3 days against Book Context's every 3 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Book Context sells 2 in-app purchases, starting at $0.99 per month and 灵线 sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Book Context ships an update every 3 weeks, 灵线 every 3 days. The most recent releases landed on October 7, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Book Context | 灵线 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Size | 5 MB | 28 MB |
| Requires iOS | **18.0** | 18.6 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [双仕 韩](https://appshunter.io/developer/1885479901) | [Hefei Yi Qicheng Technology Co., Ltd.](https://appshunter.io/developer/1895580826) |

## What reviewers say

### Book Context

[App page](https://appshunter.io/ios/app/book-context-smart-library/id6761686112)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $0.99 | per month |
| Pro Yearly | $7.99 | per year |


### 灵线

[App page](https://appshunter.io/ios/app/pdfai/id6763971571)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 月度订阅 | $4.99 | per month |
| 年度订阅 | $39.99 | per year |


## Frequently asked questions

### Is Book Context free?

Book Context is free to download, with in-app purchases available.

### Is 灵线 free?

灵线 is free to download, with in-app purchases available.

### Do Book Context or 灵线 have ads?

Neither Book Context nor 灵线 shows ads.

### Which is updated more often, Book Context or 灵线?

Book Context ships an update every 3 weeks, and 灵线 every 3 days. Most recently, Book Context was updated on October 7, 2026 and 灵线 on October 3, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*