# 순공시간 vs Stackd

The clearest difference is update cadence: Stackd at fortnightly against 순공시간's every 2 months. 순공시간's advantage is iOS requirement (15.1 vs 18). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. 순공시간 sells 2 in-app purchases, starting at $1.99 per month and Stackd sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

순공시간 ships an update every 2 months, Stackd fortnightly. The most recent releases landed on October 5, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | 순공시간 | Stackd |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Fortnightly** |
| Monetization | Freemium | — |
| Size | 34 MB | 3 MB |
| Requires iOS | **15.1** | 18 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [yerin lee](https://appshunter.io/developer/1819443165) | [Nene Nakagawa](https://appshunter.io/developer/1821103094) |

## What reviewers say

### 순공시간

[App page](https://appshunter.io/ios/app/id6748931524)

This app helps you plan your study sessions and track focused learning time. It allows you to set daily subjects, create to-do lists, and use a timer that only records actual study time. Achieve your academic goals with a clean, minimalist interface designed for smooth study flow.

**Highlights:** Subject-specific study planning, Study task checklist, Automatic focus time recording, Daily cumulative study time tracking, D-Day setting for exams, Minimalist interface

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 순공시간 프리미엄 (월간 구독) | $1.99 | per month |
| PureFocus Premium (Yearly) | $14.99 | per year |


### Stackd

[App page](https://appshunter.io/ios/app/stackd-study-timer-and-tracker/id6761293821)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Stackd Pro | $1.99 | one-time |


## Frequently asked questions

### Is 순공시간 free?

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

### Is Stackd free?

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

### Do 순공시간 or Stackd have ads?

Neither 순공시간 nor Stackd shows ads.

### Which is updated more often, 순공시간 or Stackd?

순공시간 ships an update every 2 months, and Stackd fortnightly. Most recently, 순공시간 was updated on October 5, 2026 and Stackd on October 1, 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.*