# 쪽잠 Pro vs ShiftRhythm

The clearest difference is in-app purchases: 쪽잠 Pro at none against ShiftRhythm's 3. ShiftRhythm's advantage is update cadence (every 2 days vs every 3 weeks) and device support (3 vs 1). On price, review sentiment, ads and iOS requirement there is nothing between them.

Both are free to download. ShiftRhythm sells 3 in-app purchases, starting at $2.99 per month. 쪽잠 Pro asks for nothing beyond the download.

쪽잠 Pro ships an update every 3 weeks, ShiftRhythm every 2 days. The most recent releases landed on October 12, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | 쪽잠 Pro | ShiftRhythm |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.8 (4 ratings)](https://appshunter.io/ios/app/pro/id6767180257/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 9 MB | 16 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Yechan Gu](https://appshunter.io/developer/1879393081) | [Jaeyoun Kim](https://appshunter.io/developer/6772886377) |

## What reviewers say

### 쪽잠 Pro

[App page](https://appshunter.io/ios/app/pro/id6767180257)

This app provides a quiet nap timer for short rests, allowing custom duration settings. It plays alarms only through earphones for discreet use in quiet environments and displays remaining time on the lock screen and Dynamic Island.

**Highlights:** Custom nap time setting, Quick selection for common durations, Earphone-only alarm playback, Lock screen and Dynamic Island display, Adjustable system volume within the app, 5-minute interval repeat alarm

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

**In-app purchases:** none


### ShiftRhythm

[App page](https://appshunter.io/ios/app/shiftrhythm-shift-sleep/id6776639759)

This app helps night shift workers optimize their sleep and light exposure based on their unique roster. It provides personalized guidance for sleep, naps, and light timing to align with your body clock and manage sleep debt.

**Highlights:** Personalized sleep and nap timing, Light exposure guidance, Circadian rhythm dial, Sleep score and debt tracking, Roster presets and custom schedules, Apple Watch app and widgets

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $2.99 | per month |
| Yearly | $14.99 | per year |
| Lifetime | $39.99 | one-time |


## Frequently asked questions

### Is 쪽잠 Pro free?

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

### Is ShiftRhythm free?

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

### Do 쪽잠 Pro or ShiftRhythm have ads?

Neither 쪽잠 Pro nor ShiftRhythm shows ads.

### Which is updated more often, 쪽잠 Pro or ShiftRhythm?

쪽잠 Pro ships an update every 3 weeks, and ShiftRhythm every 2 days. Most recently, 쪽잠 Pro was updated on October 12, 2026 and ShiftRhythm on October 8, 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.*