# 答案之书 vs Reverse Audio Challenge

The clearest difference is review sentiment: Reverse Audio Challenge at 61% against 答案之书's 17%. Reverse Audio Challenge also leads on update cadence (every 2 weeks vs every 12 months). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. 答案之书 sells 1 one-off in-app purchase and Reverse Audio Challenge sells 4 in-app purchases, starting at $0.49 per year. Whichever you choose, the download price is not the number that matters.

答案之书 ships an update every 12 months, Reverse Audio Challenge every 2 weeks. The most recent releases landed on October 15, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | 答案之书 | Reverse Audio Challenge |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.5 (173 ratings)](https://appshunter.io/ios/app/reverse-audio-challenge/id1486564811/reviews)** |
| Number of ratings | — | **173** |
| Positive reviews | 16.7% of reviews | **60.6% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 12 months | **Every 2 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 6 MB | 56 MB |
| Requires iOS | 15.0 | 15 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [唯墨科技](https://appshunter.io/developer/1240699340) | [Hangzhou Onedium Technology Co., Ltd.](https://appshunter.io/developer/1395700698) |

## What reviewers say

### 答案之书

[App page](https://appshunter.io/ios/app/id1475703134)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 解锁无限问题 | $0.99 | one-time |


### Reverse Audio Challenge

[App page](https://appshunter.io/ios/app/reverse-audio-challenge/id1486564811)

Record your voice, reverse it, and challenge friends to guess the original message. Explore fun sound effects, reverse text, and even play your favorite songs backward. A popular social game for endless entertainment.

**Highlights:** Record and reverse voice messages, Guess reversed messages, Mimic and re-reverse voices, Fun sound effects, Reverse text messages, Hot Words module for ideas, Music reversal

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 解锁应用内全部功能 | $0.49 | per year |
| 解锁应用内全部功能 | $1.99 | per year |
| 升级为 PRO | $0.99 | one-time |
| 升级为 PRO | $2.99 | one-time |


## Frequently asked questions

### Is 答案之书 free?

答案之书 is free to download, with in-app purchases available.

### Is Reverse Audio Challenge free?

Reverse Audio Challenge is free to download, with in-app purchases available.

### Do 答案之书 or Reverse Audio Challenge have ads?

Both 答案之书 and Reverse Audio Challenge show ads.

### Which is updated more often, 答案之书 or Reverse Audio Challenge?

答案之书 ships an update every 12 months, and Reverse Audio Challenge every 2 weeks. Most recently, 答案之书 was updated on October 15, 2026 and Reverse Audio Challenge on October 17, 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.*