# 简研 vs R90 Sleepytime

The clearest difference is price: 简研 at Free against R90 Sleepytime's $0.99. 简研 also leads on iOS requirement (10.0 vs 17.0). R90 Sleepytime's advantage is update cadence (every 4 days vs every 5 weeks). On ads, in-app purchases and device support there is nothing between them.

简研 is free to download; R90 Sleepytime costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

简研 ships an update every 5 weeks, R90 Sleepytime every 4 days. The most recent releases landed on October 29, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | 简研 | R90 Sleepytime |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 4 days** |
| Monetization | — | Free |
| Size | 101 MB | 72 MB |
| Requires iOS | **10.0** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Shanghai Mudi Biotech Co., Ltd.](https://appshunter.io/developer/1008561790) | [志加 徐](https://appshunter.io/developer/1868269300) |

## What reviewers say

### 简研

[App page](https://appshunter.io/ios/app/id1361002001)

**Features:** macOS Compatibility

**In-app purchases:** none


### R90 Sleepytime

[App page](https://appshunter.io/ios/app/r90-sleepytime/id6757743725)

This app calculates optimal sleep and wake times based on scientific sleep cycles. It also offers guided meditations and soothing sounds to help you relax and fall asleep faster.

**Highlights:** Sleep cycle calculation, Optimal wake time suggestions, Soothing sleep music, Guided meditation, Anxiety relief, Relaxation techniques

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

**In-app purchases:** none


## Frequently asked questions

### Is 简研 free?

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

### Is R90 Sleepytime free?

R90 Sleepytime costs $0.99, with no in-app purchases.

### Do 简研 or R90 Sleepytime have ads?

Neither 简研 nor R90 Sleepytime shows ads.

### Which is updated more often, 简研 or R90 Sleepytime?

简研 ships an update every 5 weeks, and R90 Sleepytime every 4 days. Most recently, 简研 was updated on October 29, 2026 and R90 Sleepytime on October 31, 2026.

---

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