# KKUK - Lock Screen Habits — Stamp it, keep it

> Habit tracking app with a unique stamp-based calendar interface. (iPhone/iPad app by Sangcheol Kim.)

- Source: https://appshunter.io/ios/app/kkuk-lock-screen-habits/id6797384948 (this page in markdown: same URL + `.md`)
- Developer: [Sangcheol Kim](https://appshunter.io/developer/6786085612)
- Category: Productivity, Lifestyle
- Price: Free
- Age rating: 4+
- Requires: iOS 18.0 · 82 MB
- Languages: Korean, American English, Japanese
- Released: 2026-08-13
- Data updated: 2026-10-10
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/kkuk-lock-screen-habits/id6797384948/reviews.md

## What is KKUK?

A to-do list erases what you finish. KKUK does the opposite — every day you follow through leaves one more stamp.

Press one stamp today. Then watch them stack up on the calendar.

■ Press it without opening the app
Open the app once and today's board appears on the Lock Screen and in the Dynamic Island. For a while after that you can press a stamp right there, without going back to the app. You can also press one from a Home Screen widget.

■ A press, not a tap
One quick tap won't do it. Hold your finger until the ink fills all the way, and the stamp lands. Slide your finger aside to cancel a press you didn't mean.

■ Make your own stamp
Build a stamp from 16 colors and an emoji. Which weekdays, how many times a day, which group it belongs to, and when it should remind you — set all of it per stamp.

■ See what you've kept
· Calendar — every stamp you pressed this month on a single board.
· Journal — leave a note and a photo beside the stamp.
· Report — see how well you kept up by week, by month, and by year. The period you're looking at can be exported as a CSV file.
· Monthly review — look back on the month that just ended.

■ Seven Home Screen widgets
Today's Stamps · Recent check-ins · Calendar · Weekly report · Monthly report · Group weekly · Large calendar. Pick any size and keep it on your Home Screen.

■ Make it yours
Twenty bundled typefaces — four drawn for Latin text, sixteen Korean. Light, dark, or follow your device. Portrait only.

■ Free to use
3 stamps, 3 groups, the last 30 days of records, this week's and this month's report, and the Today's Stamps widget. Watch a rewarded ad all the way through to add one more stamp, and the slot you earned stays yours.

■ KKUK Premium unlocks
· Unlimited stamps and groups
· Every record, including anything older than 30 days
· Past reports and past monthly reviews
· All seven widgets
· iCloud sync to continue on another device
· No ads

■ Subscription details
· KKUK Premium Monthly — $1.99 / month
· KKUK Premium Yearly — $12.99 / year

Subscriptions renew automatically. Unless canceled at least 24 hours before the current period ends, a subscription renews at the same price, and payment is charged to your Apple Account at confirmation of purchase. You can manage or cancel subscriptions in Settings > Apple Account > Subscriptions on your device.

Terms of Use https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy https://kkuk-app.web.app/en/privacy/

■ Your records stay on your device
Stamps, notes, and photos are stored on your device. There is no account and no sign-in. iCloud sync is off by default, and when you turn it on, records are copied only to your own private iCloud database. The developer cannot read them and does not keep them on a separate server.

## Key features

- Stamp habits on a calendar
- Customizable stamps with colors and emojis
- Lock screen and widget integration
- Journal entries with photos and notes
- Weekly, monthly, and yearly reports
- CSV export of reports
- Home screen widgets

## Is KKUK safe?

Not enough ratings yet to assess KKUK.

## Is KKUK legit?

KKUK - Lock Screen Habits appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for KKUK is 65 out of 100 points across 7 verification signals from App Store and developer data.

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/kkuk-lock-screen-habits/id6797384948/reviews.md

### 5/5 — 좋아요

*2026-08-28*

미션 성공 하고 저 스스로에게 선물 줍니다

**Developer response:** 안녕하세요~! ssinnal 님. 소중한 리뷰 감사 드립니다! 앞으로도 꾹으로 계속 발전 하길 바라요 💚

## Frequently asked questions about KKUK

### What is 꾹's main purpose?

꾹 is designed to help users track their habits by stamping them on a calendar. It focuses on visualizing progress by accumulating stamps over time, offering a unique alternative to traditional to-do list apps.

### Can I stamp habits without opening the 꾹 app?

Yes, once the app is opened, today's stamp board appears on the lock screen and Dynamic Island. You can stamp directly from there without returning to the app, and also via home screen widgets.

### How does 꾹 handle habit creation?

You can create personalized stamps using 16 different colors and emojis. For each stamp, you can specify the days of the week, frequency, group, and set reminder times.

### What reporting features does 꾹 offer?

꾹 provides a calendar view for the current month's stamps, a Journal feature for daily notes and photos, and reports for weekly, monthly, and yearly habit adherence. Reports can be exported as CSV files.

### Does 꾹 have ads?

Yes, 꾹 contains advertisements, as indicated by its 'hasAds' flag.

### What platforms is 꾹 available on?

꾹 is supported on Apple Watch and iPhone, as indicated by its 'supportedDevices' field.

### How is my data stored in 꾹?

Stamps, notes, and photos are stored locally on your device. iCloud synchronization is off by default but can be enabled to replicate data to your private iCloud database; the developer cannot access this data.

### What is the update frequency of 꾹?

The latest version, 1.5.0, was released on September 16, 2026, indicating a recent update. The app was initially released on August 13, 2026.

## Version history (last 5 releases)

### 1.7.0 — 2026-10-01

■ Rest days
Pick a date in Calendar and set it as a rest day. Rest days are left out of your completion rate, and your streak doesn't break.
Rest days are a KKUK Premium feature. If your subscription ends, the rest days you set are kept, but they no longer count in your stats.

### 1.6.1 — 2026-09-29

● 소소한 버그 및 앱 사용성을 개선했어요.

### 1.6.0 — 2026-09-21

■ 일본어를 지원해요 — iPhone 언어가 일본어면 앱과 위젯, Apple Watch가 모두 일본어로 보여요. 설정 → 앱 → 꾹 → 언어에서 꾹만 일본어로 바꿀 수도 있어요.

### 1.5.0 — 2026-09-16

■ Set a finish line for a stamp
Pick an end — 30 days, or 100 times — on the New stamp or Edit stamp screen. The stamp's detail and Report show how far along you are. It's free.

■ Your past records count
Add a finish line later and nothing resets. A stamp you've kept for a while starts out well along.

■ A celebration when you get there
Fill what you set and KKUK celebrates. Keep stamping after that.

### 1.4.0 — 2026-09-10

■ 64 ink colors
KKUK Premium now includes the Pastel, Summer and Autumn themes. On the New stamp screen, pick a theme to see its colors.

## Apps similar to KKUK

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [그로브 노트](https://appshunter.io/ios/app/id6796952609) | — | Free | Productivity |
| [기록해 - 순간을 담다](https://appshunter.io/ios/app/id6756781813) | — | Free | Productivity |
| [WiCal - Widget Calendar](https://appshunter.io/ios/app/wical-widget-calendar/id6751499983) | — | Free | Productivity |
| [nowNote](https://appshunter.io/ios/app/nownote/id6475732731) | — | $1.99 | Productivity |
| [Lume Flow](https://appshunter.io/ios/app/lume-flow/id6787862341) | — | Free | Productivity |
| [쓰던달력](https://appshunter.io/ios/app/id6797215169) | — | Free | Productivity |

## More apps by Sangcheol Kim

- [PhotoChagok – Photo Organizer](https://appshunter.io/ios/app/photochagok-photo-organizer/id6786085610)
- [멍냥첫날 - 강아지 고양이 예방접종 일정](https://appshunter.io/ios/app/id6809621004)
- [GoodokMoa - Easy subscriptions](https://appshunter.io/ios/app/goodokmoa-easy-subscriptions/id6810900822)
- [Number Baseball Duel - Puzzle](https://appshunter.io/ios/app/number-baseball-duel-puzzle/id6815732897)
- [BingoBoo - Number Bingo Battle](https://appshunter.io/ios/app/bingoboo-number-bingo-battle/id6817169614)

All apps by Sangcheol Kim: https://appshunter.io/developer/6786085612

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-10.*