# Voice Recorder vs 知识树

The clearest difference is update cadence: 知识树 at every 5 days against Voice Recorder's every 7 months. 知识树 also leads on review sentiment (39% vs 14%). Voice Recorder's advantage is monetization model (free vs freemium). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Voice Recorder sells 1 in-app purchase, starting at $9.99 per year and 知识树 sells 4 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

Voice Recorder ships an update every 7 months, 知识树 every 5 days. The most recent releases landed on September 20, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Voice Recorder | 知识树 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.2 (5 ratings)](https://appshunter.io/ios/app/ai/id6505133670/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | 14.3% of reviews | **38.9% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 5 days** |
| Monetization | **Free** | Freemium |
| Size | 3 MB | 2 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Alteru Inc.](https://appshunter.io/developer/434747758) | [野 匡](https://appshunter.io/developer/819954894) |

## What reviewers say

### Voice Recorder

[App page](https://appshunter.io/ios/app/voice-recorder/id297101093)

This app offers a streamlined audio recording experience for lectures, meetings, and personal notes. It allows for easy recording, note-taking during sessions, and AI-powered outline generation for summarization. Recordings can be organized and shared efficiently.

**Highlights:** Easy one-tap recording, Pause and resume recording, Take notes during recording, AI-powered outline generation, Organize recordings by name, date, size, Background recording and playback, Share recordings easily

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Voice Recorder Yearly Subscription | $9.99 | per year |


### 知识树

[App page](https://appshunter.io/ios/app/ai/id6505133670)

This intelligent learning system uses AI to understand knowledge, break down concepts, and dynamically schedule practice and review based on your memory state. It focuses on true retention through spaced repetition and scientific memory curves, not just completing exercises.

**Highlights:** AI-driven knowledge understanding, Dynamic practice and review scheduling, Breakdown of knowledge into testable points, Spaced repetition for long-term memory, Automatic assessment of mastery, Progress tracking over speed

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 月度会员 | $2.99 | per month |
| 季度会员 | $4.99 | per 3 months |
| 年度会员 | $19.99 | per year |
| 终身会员 | $24.99 | one-time |


## Frequently asked questions

### Is Voice Recorder free?

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

### Is 知识树 free?

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

### Do Voice Recorder or 知识树 have ads?

Neither Voice Recorder nor 知识树 shows ads.

### Which is updated more often, Voice Recorder or 知识树?

Voice Recorder ships an update every 7 months, and 知识树 every 5 days. Most recently, Voice Recorder was updated on September 20, 2026 and 知识树 on September 23, 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.*