# NDAA vs 随心背诵

The clearest difference is update cadence: NDAA at every 3 weeks against 随心背诵's every 4 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. NDAA sells 10 one-off in-app purchases and 随心背诵 sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

NDAA ships an update every 3 weeks, 随心背诵 every 4 months. The most recent releases landed on September 29, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | NDAA | 随心背诵 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 4 months |
| Size | 63 MB | 44 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Beijing Intelligent Meeting Solution, Ltd](https://appshunter.io/developer/1403224760) | [Metademy](https://appshunter.io/developer/1675831131) |

## What reviewers say

### NDAA

[App page](https://appshunter.io/ios/app/ndaa/id1403224761)

**Features:** macOS Compatibility

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 30 学币 | $4.99 | one-time |
| 68 学币 | $9.99 | one-time |
| 108 学币 | $15.99 | one-time |
| 188 学币 | $27.99 | one-time |
| 288 学币 | $45.99 | one-time |
| 588 学币 | $89.99 | one-time |
| 998 学币 | $149.99 | one-time |
| 1998 学币 | $299.99 | one-time |
| 2998 学币 | $449.99 | one-time |
| 4998 学币 | $799.99 | one-time |


### 随心背诵

[App page](https://appshunter.io/ios/app/id6740698706)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 60天会员 | $0.99 | one-time |
| 28天会员 | $3.99 | one-time |


## Frequently asked questions

### Is NDAA free?

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

### Is 随心背诵 free?

随心背诵 is free to download, with in-app purchases available.

### Do NDAA or 随心背诵 have ads?

Neither NDAA nor 随心背诵 shows ads.

### Which is updated more often, NDAA or 随心背诵?

NDAA ships an update every 3 weeks, and 随心背诵 every 4 months. Most recently, NDAA was updated on September 29, 2026 and 随心背诵 on October 9, 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.*