# 咖博士 vs 背壳锁 BK

The clearest difference is update cadence: 背壳锁 BK at daily against 咖博士's every 3 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

咖博士 ships an update every 3 months, 背壳锁 BK daily. The most recent releases landed on September 26, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | 咖博士 | 背壳锁 BK |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Daily** |
| Size | 49 MB | 86 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Suzhou ChisalSoft Technology Co., Ltd.](https://appshunter.io/developer/786990357) | [广东必达保安系统有限公司](https://appshunter.io/developer/1252551530) |

## What reviewers say

### 咖博士

[App page](https://appshunter.io/ios/app/id6444034192)

**Features:** Vision Pro support

**In-app purchases:** none


### 背壳锁 BK

[App page](https://appshunter.io/ios/app/bk/id6753927706)

**In-app purchases:** none


## Frequently asked questions

### Is 咖博士 free?

咖博士 is free to download, with no in-app purchases.

### Is 背壳锁 BK free?

背壳锁 BK is free to download, with no in-app purchases.

### Do 咖博士 or 背壳锁 BK have ads?

Neither 咖博士 nor 背壳锁 BK shows ads.

### Which is updated more often, 咖博士 or 背壳锁 BK?

咖博士 ships an update every 3 months, and 背壳锁 BK daily. Most recently, 咖博士 was updated on September 26, 2026 and 背壳锁 BK on September 22, 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.*